In October 2017, Sane made her television debut on NXT, defeating Aliyah.
In November, at NXT TakeOver: WarGames, Sane competed in a fatal four–way match for the vacant NXT Women's Championship.
but was unsuccessful as Ember Moon won the match.

On January 28, 2018, at the Royal Rumble, Sane participated in the first women's Royal Rumble match, entering at number 6 and lasting around 5 minutes before being eliminated by Dana Brooke.
A few months later, she also participated in the WrestleMania Women's Battle Royal at WrestleMania 34, alongside other NXT superstars, but was eliminated from the match by Sasha Banks.
Shortly after, Sane started a feud with Lacey Evans as the two exchanged victories and attacked each other throughout the next few weeks.
Eventually, Sane was able to defeat Evans on the June 6 episode of NXT, in a final match between the two, to end their feud.

In July, after she defeated Candice LeRae and Nikki Cross in a triple–threat match to become the number one contender, Sane reignited her rivalry with Shayna Baszler, as the two exchanged victories in the Mae Young Classic Finals and at NXT and faced off in a match at NXT TakeOver: Brooklyn IV on August 18 where Sane was able to defeat Bazsler to win the NXT Women's Championship for the first time in her career.
On October 28, at the WWE Evolution pay–per–view, Sane lost the championship back to Baszler (after interference from her allies Jessamyn Duke and Marina Shafir) ending her reign at 71 days.
Three weeks later, at NXT TakeOver: WarGames, Sane received her rematch against Baszler in a two out of three falls match, but she failed to regain the title after interference from Duke and Shafir again.
Because of the interferences, Sane eventually aligned with her best friend Io Shirai and Dakota Kai against Baszler, Duke and Shafir.
Shortly after, Kai was sidelined with an injury and Sane continued to team with Shirai, forming a tag team known as "The Sky Pirates" while continuing to defeat various teams.

On April 5, 2019, at NXT TakeOver: New York, Sane competed in a fatal–four way match for the NXT Women's Championship, however, she was unsuccessful in capturing the title as Baszler submitted Bianca Belair to retain.
Just six days later, on April 11 (episode aired on tape delay on April 17), Sane lost a rematch to Baszler after Io Shirai attacked Baszler who was looking to injure Sane.
Because of her loss, Sane is not allowed to challenge for the NXT Women's Championship anymore, which was a way to write her off the brand.
In October 2017, Sane made her television debut on NXT, defeating Aliyah. In November, at NXT TakeOver: WarGames, Sane competed in a fatal four–way match for the vacant NXT Women's Championship. but was unsuccessful as Ember Moon won the match.
On January 28, 2018, at the Royal Rumble, Sane participated in the first women's Royal Rumble match, entering at number 6 and lasting around 5 minutes before being eliminated by Dana Brooke. A few months later, she also participated in the WrestleMania Women's Battle Royal at WrestleMania 34, alongside other NXT superstars, but was eliminated from the match by Sasha Banks. Shortly after, Sane started a feud with Lacey Evans as the two exchanged victories and attacked each other throughout the next few weeks. Eventually, Sane was able to defeat Evans on the June 6 episode of NXT, in a final match between the two, to end their feud.
In July, after she defeated Candice LeRae and Nikki Cross in a triple–threat match to become the number one contender, Sane reignited her rivalry with Shayna Baszler, as the two exchanged victories in the Mae Young Classic Finals and at NXT and faced off in a match at NXT TakeOver: Brooklyn IV on August 18 where Sane was able to defeat Bazsler to win the NXT Women's Championship for the first time in her career. On October 28, at the WWE Evolution pay–per–view, Sane lost the championship back to Baszler (after interference from her allies Jessamyn Duke and Marina Shafir) ending her reign at 71 days. Three weeks later, at NXT TakeOver: WarGames, Sane received her rematch against Baszler in a two out of three falls match, but she failed to regain the title after interference from Duke and Shafir again. Because of the interferences, Sane eventually aligned with her best friend Io Shirai and Dakota Kai against Baszler, Duke and Shafir. Shortly after, Kai was sidelined with an injury and Sane continued to team with Shirai, forming a tag team known as "The Sky Pirates" while continuing to defeat various teams.
On April 5, 2019, at NXT TakeOver: New York, Sane competed in a fatal–four way match for the NXT Women's Championship, however, she was unsuccessful in capturing the title as Baszler submitted Bianca Belair to retain. Just six days later, on April 11 (episode aired on tape delay on April 17), Sane lost a rematch to Baszler after Io Shirai attacked Baszler who was looking to injure Sane. Because of her loss, Sane is not allowed to challenge for the NXT Women's Championship anymore, which was a way to write her off the brand.
Kairi Sane