On August 22, 2015, Asuka attended WWE's NXT TakeOver: Brooklyn event in Brooklyn, New York, Rumours about her having signed with WWE were soon confirmed at a press conference on September 8 in Tokyo. She then joined WWE's developmental territory NXT. Her debut appearance, which aired on September 23, ended in a confrontation with Dana Brooke and Emma. In her debut match on October 7 at NXT TakeOver: Respect, Asuka defeated Dana. Asuka continued racking victories over various wrestlers, including main roster performer Cameron, and continued her feud with Dana Brooke and Emma. On December 16 at NXT TakeOver: London, Asuka defeated Emma.
On the January 13, 2016 episode of NXT, Asuka participated in a battle royal to determine the number one contender for Bayley's NXT Women's Championship; she was eliminated second-to-last by Eva Marie. On the February 10 episode, battle royal winner Carmella lost her title match against Bayley. Asuka saved Carmella from a post-match attack by Eva Marie and Nia Jax and afterwards had a staredown with Bayley, indicating that she wanted a shot at her title. On April 1, Asuka defeated Bayley by technical submission to win the NXT Women's Championship at NXT TakeOver: Dallas and successfully defended the title against Nia Jax on June 8 at NXT TakeOver: The End.
Asuka then rekindled her feud with Bayley, whom she again defeated on August 20 at NXT TakeOver: Brooklyn II. After her successful title defense against Mickie James on November 19 at NXT TakeOver: Toronto, Asuka displayed the first signs of villainous behavior when she refused to shake her opponent's hand after the match. On the January 11, 2017 episode of NXT when Asuka was overpowered by The Iconic Duo (Billie Kay and Peyton Royce), Nikki Cross came to her rescue but then herself attacked Asuka. Asuka demanded to defend her title against all three and won the subsequent fatal four-way match on January 28 at NXT TakeOver: San Antonio. In early February, Asuka became the longest-reigning singles champion in NXT history, male or female. In March, Asuka wrestled on several house shows with WWE's main roster as a replacement for an injured Naomi, including a show at Madison Square Garden on March 12. Around this time, WWE began promoting Asuka's "undefeated streak since her arrival" in NXT. Asuka had never lost a match by submitting or being pinned, though she had come up short in the aforementioned battle royal in January 2016, a tag team match, and one fatal four-way match on NXT house shows in March and May 2016, respectively, when other wrestlers were pinned.
In her successful title defense against Ember Moon on April 1, 2017 at NXT TakeOver: Orlando, Asuka again behaved like a villainess, shoving the referee into her opponent to avoid Moon's finishing maneuver (the Eclipse) en route to winning the match. Asuka also attacked Ember Moon, Nikki Cross and Ruby Riot, who were the final competitors in a battle royal to determine her challenger for NXT TakeOver: Chicago. Subsequently, Asuka had to defend her title against Nikki Cross and Ruby Riot in a triple threat match (Ember Moon missed out on the match due a shoulder injury), but she managed to retain her title at the event on June 20. In June, Asuka decisively defeated Nikki Cross in a Last Woman Standing match to retain her championship. During that time, she surpassed Goldberg's winning streak and Rockin' Robin's record-setting 502 day WWF Women's Championship reign.
On August 19 at NXT TakeOver: Brooklyn III, Asuka defeated the returning Ember Moon to retain her title. However, during the match she broke her right collarbone which forced her out of action for six to eight weeks, thus Asuka had to relinquish the NXT Women's Championship at the August 24 NXT tapings which aired on September 6, ending her reign at 510 days. During her farewell segment, NXT General Manager William Regal called her "one of the greatest champions in WWE history" and also mentioned negotiations to move Asuka to WWE's main roster.
After multiple vignettes in the upcoming weeks, it was revealed on the September 11, 2017, episode of Raw, Asuka was assigned to the Raw brand. A month later, on October 22, at TLC: Tables, Ladders & Chairs, Asuka defeated her old rival Emma in her in–ring debut. On November 19 at Survivor Series, Asuka represented Team Raw in a Survivor Series match against Team SmackDown and was the sole survivor, lastly eliminating Tamina and Natalya. Throughout the next few months, Asuka continued her streak by defeating the likes of Dana Brooke (whom she defeated in three seconds, setting a new WWE record for the fastest submission win in a women's match), Alicia Fox and Raw Women's Champion Alexa Bliss in a non–title match.
On January 28, 2018 at the Royal Rumble, Asuka won the first women's Royal Rumble match, entering at number 25 and eliminating her former rival Ember Moon and lastly Nikki Bella to earn herself a women's championship match at WrestleMania 34. Throughout January and February, Asuka started a feud with Nia Jax, who attacked her during and before her matches and wanted her title opportunity at WrestleMania. Asuka defeated Nia Jax on February 25 at Elimination Chamber and again on the March 5 episode of Raw. In parallel, she also took a part of the Mixed Match Challenge tournament, with The Miz as her partner in support of the charity Rescue Dogs Rock. With wins over Carmella and Big E, Sasha Banks and Finn Bálor, Alexa Bliss and Braun Strowman and finally Charlotte Flair and Bobby Roode, they won the tournament. After Flair retained the SmackDown Women's Championship against Ruby Riott on March 11 at Fastlane, Asuka challenged Charlotte for the SmackDown Women's Championship at WrestleMania 34. At the event on April 8, Asuka submitted to Charlotte, ending her WWE undefeated streak at 914 days.
On April 17, Asuka was drafted to SmackDown as part of the 2018 WWE Superstar Shake-up, making her first appearance by saving Charlotte Flair and Becky Lynch from an attack by The IIconics (Billie Kay and Peyton Royce) and then—SmackDown Women's Champion Carmella. On the May 15 episode of SmackDown Live, Smackdown General Manager Paige interrupted Carmella, to announce that she would be defending the SmackDown Women's Championship against Asuka at Money in the Bank. At the event, on June 17, Asuka lost to Carmella after an interference from the returning James Ellsworth, suffering her first official pinfall loss in WWE. Paige then granted Asuka a rematch, that took place on July 15 at Extreme Rules, which Asuka lost as well after another distraction from Ellsworth, who was hanging above the ring in a shark cage, which Carmella used to win the match. In September, Asuka helped Naomi, who after defeating Peyton Royce was attacked by The IIconics. This led to a tag team match between the two teams on October 6 at WWE Super Show-Down, where Asuka and Naomi were defeated. Also during that time, it was announced that Asuka and The Miz would take part in the upcoming season two of Mixed Match Challenge. They would last until the semifinals, where they were eliminated by eventual winners R-Truth and Carmella. On November 18, Asuka took part in the Survivor Series as part of Team Smackdown, where she was the last woman eliminated on Team SmackDown.
Towards the end of November, Asuka won a battle royal to enter her way into the first ever women's Tables, Ladders, and Chairs match against both Becky Lynch and Charlotte Flair for the SmackDown Women's Championship. On December 16, at the namesake event, in what was also the first ever women's championship match to main event a dual–branded event, Asuka won the SmackDown Women's Championship for the first time in her career after Ronda Rousey interfered and pushed Lynch and Flair off a ladder. In her first title defense, two days later, Asuka defeated fellow babyface Naomi. Throughout her reign, Asuka was able to fend off challengers such as Becky Lynch and Mandy Rose at the January and March pay-per-view events respectively. On the March 26 episode of SmackDown, Charlotte Flair defeated Asuka to win the SmackDown Women's Championship, ending her reign at 100 days.
On the April 16th edition of SmackDown Live, it was announced that Asuka would be entering the WWE women’s tag team division, teaming with the newly debuted Kairi Sane from NXT as the Kabuki Warriors and being managed by Paige. In June, the Kabuki Warriors started a feud with the Women's Tag Team Champions, the IIconics whom they defeated in Tokyo. After weeks of dodging by the IIconics, the Kabuki Warriors were granted their title match on the July 16 episode of SmackDown which they won by count out. However, the IIconics retained their titles. On the August 5 episode of Raw, the Kabuki Warriors participated in a fatal four way elimination tag team match for the Women's Tag Team Championship but were the last ones eliminated by Alexa Bliss and Nikki Cross.
After a short hiatus, The Kabuki Warriors returned in September and defeated Mandy Rose and Sonya Deville. On October 6, at the Hell in a Cell pay–per–view, The Kabuki Warriors finally won the Women's Tag Team Championship from Bliss and Cross, after Asuka used a green mist on Cross. The next night on Raw, The Kabuki Warriors completed their transition into heels, as they cut a promo on both Becky Lynch and Charlotte Flair and went onto defeat them in a non–title match, once again using green mist as leverage. As part of the 2019 Draft in mid-October, Asuka and Sane were both drafted to the Raw brand. The duo further solidified their heel turn after Asuka sprayed green mist on their manager Paige on the October 28, 2019 episode of Raw. At the Royal Rumble, Asuka failed to win the WWE Raw Women's Championship after Lynch kicked Asuka causing her to spit her green mist in the air and into her own face. On the February 3, 2020 episode of Raw, Asuka demanded a rematch for the title, in which Lynch accepted, but a week later on Raw, Asuka again failed to win the title.
On the first night of WrestleMania 36, The Kabuki Warriors (Asuka and Kairi Sane) lost their Women's Tag Team Championships to the team of Nikki Cross and Alexa Bliss. This ended their reign at 181 days. On the March 13, 2020 episode of Raw, Asuka qualified for the Money in the Bank ladder match after defeating Ruby Riott. At the event, Asuka won the women's Money in the Bank contract. The following night on Raw, Raw Women's Champion Becky Lynch revealed that she had vacated the title due to pregnancy, and that the ladder match was in fact for the vacated Raw Women's Championship rather than a contract, making Asuka the new champion, and showing signs of a face turn, as she celebrated with and hugged Lynch. On the next Raw, The Kabuki Warriors officiated their face turn, beginning a feud with Nia Jax. At Backlash, Asuka retained the title after both her and Jax were counted out. A rematch was scheduled the following night on Raw, where Asuka retained the title once again with a roll up pin and a fast count. Asuka presumably lost the Raw Women’s Championship at The Horror Show at Extreme Rules, where she was pinned by Sasha Banks in her title defense after she indirectly blinded the referee with the green mist and Bayley removed the referee’s shirt, put it on herself, and counted the pinfall, although the next night on Raw, it was declared an unofficial title change. However, the following week, Asuka officially lost the title via count out in their rematch, where the belt could change hands by pinfall, submission, count out, disqualification or interference. Sasha Banks won the title when Asuka chose to get herself counted out to save her tag team partner, Kairi Sane, from an attack by Bayley. This also marked Sane’s final appearance in WWE, as she left the company directly after.
Asuka won a triple-brand battle royal on the August 14, 2020 episode of SmackDown. At SummerSlam, Asuka wrestled Bayley for the SmackDown Women's Championship, losing this match, and Sasha Banks for the Raw Women's Championship, winning this match and becoming a two-time Raw Women's Champion in the process. At Clash of Champions, Asuka defeated Zelina Vega to retain her championship and answer Bayley's open challenge for the SmackDown Women's Championship, which she won via disqualification. The following night on Raw, Asuka would face Zelina Vega for the Raw Women's Title and successfully retained. On the October 5 episode of Raw, Asuka teamed with Dana Brooke and Mandy Rose to defeat Zelina Vega, Natalya and Lana. Asuka would then enter a feud with Lana where they fought on the October 19 episode of Raw for the Raw Women's Title and Asuka would retain. Asuka would then face Sasha Banks at Survivor Series, where she would go on to lose. On the November 23 episode of Raw, Asuka would reward Lana with a Raw Women's Title opportunity after Lana's win at Survivor Series. While the match was taking place, Nia Jax and Shayna Baszler would interfere and the match would end in disqualification. Following this, Asuka and Lana teamed up and defeated Shayna Baszler and Nia Jax. On the November 30 episode of Raw, Asuka and Lana would team up once again and beat Shayna and Nia with Lana getting the pin and victory for their team.
On the December 7 episode of Raw, Asuka would face Shayna Baszler and Asuka won the match. It was announced that Asuka and Lana would take on Shayna Baszler and Nia Jax at TLC for the Women's Tag Team Titles. However the following week, Lana would be attacked by Jax and Baszler, injuring her and leaving her unable to wrestle at TLC. At the pay-per-view, Asuka revealed Charlotte Flair as her new partner, and they would go on to defeat Jax and Baszler to win the tag team titles, making Asuka a double champion, and the first woman to hold the Women's Tag Team Championships with two different partners. However, Asuka and Flair would lose the titles back to Jax and Baszler at the Royal Rumble, due to interference from Ric Flair and Lacey Evans. On the March 22 episode of Raw, Rhea Ripley confronted Asuka and challenged her to a match for the Raw Women's Championship at WrestleMania 37, which Asuka accepted. On April 11, on night two of Wrestlemania 37, Ripley defeated Asuka and ended her reign at 231 days. On the Raw after WrestleMania, Asuka faced Ripley for a title match again, in a no-contest result due to Charlotte Flair attacking both of them. On the May 3 episode, another rematch between Ripley and Asuka for the Raw Women's Championship was scheduled for WrestleMania Backlash. However, WWE official Sonya Deville added Flair to the championship match to make it a triple threat match. At the event, Asuka was unsuccessful in regaining the title as she was pinned by Ripley. On the June 21 episode of Raw, Asuka and Naomi qualified for the women's Money in the Bank ladder match by defeating the team of Eva Marie and Doudrop. At Money in the Bank, she was unsuccessful in winning the match. During the 2021 WWE Draft, Asuka was not drafted and was declared a free agent.
After nine months of inactivity due to injury, Asuka made her return on the April 25, 2022 episode of Raw, confronting Becky Lynch. On the May 9 episode, WWE official Adam Pearce gave Asuka a championship contender's match against Raw Women's Champion Bianca Belair. Lynch became upset and later attacked Asuka and Belair during their match. The following week, Asuka defeated Lynch using green mist and earned a title match for the Raw Women's Championship at Hell in a Cell. At the event, she was unsuccessful in winning the title. On the June 20 episode of Raw, Asuka defeated Lynch to qualify for the women's Money in the Bank ladder match at the eponymous event. At Money in the Bank, she was unsuccessful in winning the match. On the October 31 episode of Raw, Asuka and Alexa Bliss defeated Women's Tag Team Champions Dakota Kai and Iyo Sky in a title match to win the championships. In a rematch at Crown Jewel, Bliss and Asuka lost the titles back to Kai and Sky due to an interference from Nikki Cross. At Survivor Series WarGames, the team of Asuka, Belair, Bliss, Lynch, and Mia Yim defeated the team of Damage Control, Cross, and Rhea Ripley in a WarGames match.
At Royal Rumble on January 28, 2023, Asuka entered the women's Royal Rumble match at number seventeen, debuting a new look with shorter hair and face paint. Ultimately, she would finish in third place, being eliminated by eventual winner Rhea Ripley. At Elimination Chamber, Asuka defeated Carmella, Liv Morgan, Natalya, Nikki Cross, and Raquel Rodriguez to earn a Raw Women's Championship match against Bianca Belair at WrestleMania 39. Asuka would lose her Raw Women's Championship match against Belair on night two of WrestleMania 39. As part of the 2023 WWE Draft, Asuka was drafted to the SmackDown brand. She made her first appearance since the draft on the May 12 episode of SmackDown and used her green mist to attack Bianca Belair, turning heel in the process. Their feud led to a title rematch at Night of Champions, where Asuka defeated Belair to win the Raw Women's Championship for the third time. On the June 9 episode of SmackDown, the title was renamed to the WWE Women's Championship and Asuka was presented a brand-new championship design before being interrupted by Charlotte Flair, who challenged Asuka to a title match, which Asuka accepted and won. At SummerSlam on August 5, Asuka lost the title to Belair in a triple threat match also involving Flair, ending her third reign at 70 days. She then failed to regain the title against Iyo Sky and Flair in a triple threat match at Fastlane.
On the November 10 episode of SmackDown, during a six-woman tag team match pitting Asuka with Belair and Flair against Damage Control's Bayley, Sky and Kairi Sane, who returned at Crown Jewel and had joined the stable earlier that night, Asuka turned on her teammates to reunite with Sane while joining Damage Control at the same time. At Survivor Series: WarGames, Damage Control lost to Belair, Flair, Becky Lynch and Shotzi in a WarGames match. On the January 26, 2024 episode of SmackDown, Asuka and Sane, again competing as the Kabuki Warriors, defeated Katana Chance and Kayden Carter to win the WWE Women's Tag Team Championships for the second time (Asuka's fourth reign individually). Asuka and Sane went on to retain their titles against Chance and Carter on the February 5 episode of Raw and against Candice LeRae and Indi Hartwell on the Elimination Chamber: Perth kickoff show. At NXT Roadblock on March 5, Asuka and Sane defeated Tatum Paxley and NXT Women's Champion Lyra Valkyria to retain their titles. On night one of WrestleMania XL, Damage Control (Asuka, Sane, and Kai) were defeated by Bianca Belair, Naomi, and Jade Cargill in a six-woman tag team match. In the 2024 WWE Draft, Asuka (as apart of Damage Control) was drafted to the Raw brand. At Backlash France on May 4, Asuka and Sane lost their titles to Belair and Cargill, ending their second reign at 99 days. Two days later on Raw, it was reported that Asuka had suffered an unspecified injury and was pulled out from the Queen of the Ring tournament.