|Name (Kanji)||三橋 千夏|
|Seiyū|| Uchida, Maaya (内田 真礼)
Shannon Emerick (English)
|Novel Debut||Volume 3, Chapter 2|
|Anime Debut||Episode 11|
Mihashi Chinatsu (三橋 千夏) is Yui's old karate rival from her junior high years. Mihashi would frequently compete against Yui in their local karate tournaments, though Mihashi never managed to beat her. Mihashi would eventually move away due to her parents divorcing, but before she did, she approached Yui and they made a promise with one another that once they enter high school, they would fight each other again in the finals of the national tournament. Mihashi greatly valued their promise and was furious when she heard that Yui had quit karate.
Mihashi is shown to be a very blunt, aggressive individual who is not afraid to speak her mind. Like Yui, Mihashi is a proud and skilled practitioner of karate and can just as easily communicate with fists as she can with words.
Mihashi has long, brown hair tied back in a ponytail and dark-green eyes. She has been noted to have a very stern disposition.
- Kiriyama Yui: Although her behavior would suggest otherwise, Mihashi greatly values her past rivalry with Yui and has only the highest respect for Yui's martial art skills. Mihashi is crushed to hear that Yui had quit karate and tries desperately to get her to return back to her former "prodigy" status by reminding her of the promise they made to each other. Mihashi does not approve of Yui being in the Cultural Club, seeing it as pointless, but the two ultimately part on good terms. Mihashi later returns in time for Yamaboshi High's Couples Battle Royale and the two decide to have a special karate match. During the match, Mihashi is defeated by a move taught to Yui by Taichi, proving that her time spent in the Cultural Club was not a waste.
- Kiriyama Anzu: Despite claiming she is not friends with Yui, Mihashi is apparently familiar enough to know Anzu, and the two were shown to collaborate in their effort to get Yui back into karate. They later team up for the Couples Battle Royale as a special pair when Mihashi returns in Precious Time.