Yuki appears in various other media that doesn't necessarily tie into her The King of Fighters counterpart. She usually acts in a similar manner as her original incarnation, but she demonstrates different traits or character relationships that make her different.
Yuki remains as a constant but secondary character in the game and will with Kyo go on some dates. During one of these dates Yuki meets Shermie and ends scaring her a little. At some point, she is apparently kidnapped while waiting to meet up with Kyo for a date, and taken to several places outside Japan: Kyo must investigate with the help of other fighters, but it turns out it was a plan from Chizuru Kagura, who asked Yuki to lay low as a test of character for Kyo.
Later, Yuki is kidnapped for real by Chris and then held hostage by Yashiro Nanakase in the middle of the tournament, reflecting the Sacred Treasures subplot and revealing her heritage as Princess Kushinada's descendant to both Kyo and to herself, much to her shock. In the epilogue, the recently-rescued Yuki tends to Kyo once he wakes up, along with Shingo Yabuki and Chizuru.
Yuki enters the Queen of Fighters tournament to get her revenge on Iori Yagami. The reason for this is unknown, but it most like has something to do with Kyo. Once she confronts him, Iori (dressed as Miss X) is rather shocked to see that she managed to defeat her opponents and reach the final stage. The two fight and Yuki comes out as the winner. She nearly uses the K' Talisman to turn Iori into Miss X forever, much to the man's horror, but decides to keep hold of it just in case.
The King of Fighters' 94Edit
In the third volume of the manga, Rugal Bernstein takes notice of Yuki and has her kidnapped as a test for Kyo. Said test consists in leaving Yuki bound and gagged inside an hotel room that has a time bomb, then have Kyo and his team forced to fight and win their match with the Women's Team within a one-hour time limit before they can get her out of there. She is ultimately rescued by Kyo and thanks him, but he is worried by the danger she is put in because of their relationship. She sees him off at the airport as he leaves Japan a few days later.
Yuki is portrayed as a snarker and often impatient with Kyo, who in return treats her more as a sister than a proper girlfriend. They squabble over petty things but are still extremely loyal to each other if the need arises. Yuki doesn't even know about the existence of the King of Fighters tournament until she, Kyo, Athena and Sie Kensou meet. She's initially jealous of Athena when she introduces herself to Kyo but the two eventually become friendly rivals.
Iori Yagami comes to their school; upset by Iori's attitude and fearing that other people's safety, Yuki stops the rivals' impending fight and tells Iori to leave Kyo alone. Iori grabs her and mocks Kyo, but eventually releases her. When Iori leaves, Yuki is left shaken by the ordeal and is resentful for keeping his involvement in the tournament a secret.
Later her friend, Sanae, introduces Yuki to Maeta, who has had a crush on her. When Maeta defeats Kyo in a judo match, he wins the chance to date her. During their date she's kidnapped by a masked man on a motorcycle. The man ties Yuki up the top of a lamp post and challenges Kyo. During the fight, Kyo realizes the importance of his powers as a tool to protect his loved ones. His father, satisfied with his son's revelation, releases Yuki, and she falls into Kyo's arms.
In the last volume, Athena asks Yuki and Kyo to join her and Kensou in the school festival. She agrees to play the keyboards while Athena sings and Kyo and Kensou play guitar. However the festival is crashed by Goenitz, who has just defeated and kidnapped Iori; Chizuru Kagura appears as well and tries to strike a deal. Goenitz responds via giving her and Kyo some time to get ready, but takes Yuki as a hostage as well. Yuki is upset when she witnesses Goenitz torture Iori, but ultimately both of them are rescued by Kyo.