Mitsuru, or commonly known as Mitchan, is Shigure Sohma's editor, and a big object of his teasing. Her surname is never mentioned in the story.
She goes insane when Shigure disappears right before his deadlines (which he does on a regular basis), and writes suicide notes on his front steps. She has also threatened to kill herself while kneeling on his front porch. Before she had found out that Shigure likes to play with her, she found him quite "handsome and attractive". Now, she describes him as "a devil floating in the sea on a boat, disguised as a human".
Mitchan keeps extremely short brown hair and is often seen dressed in office clothing. She also has brown eyes.
Before Summer Vacation
She met Ritsu Sohma while he was going to visit Shigure. They may have started dating, since they are shown having instant chemistry, but it is revealed in a side story in the Fruits Basket Fanbook -Cat- that Mitsuru is not entirely sure of Ritsu's gender, due to his constant wearing of women's kimonos.
After Summer Vacation
Mitchan is Shigure's editor. Shigure teases Mitchan about getting his paperwork done (ex. playing around the house saying he doesn't have anything done to annoy Mitchan, while actually having it all done).
Ritsu and Mitchan meet while yelling at Shigure. They end up as a couple. It is never stated whether or not she is aware of the curse (and judging by the two character's personalities, she most likely does not know). In an Omake it is revealed slightly jokingly that she is not 100% sure that Ritsu is a man (and likewise, Ritsu is almost doubly self-conscious about his crossdressing around Mitchan) but the two seem very happy anyway. It is revealed the two are very far along in their relationship due to when Ritsu's curse was broken Mitchan was there with his parents.
- She is unaware of the Zodiac curse.
- She is always shown complaining about Shigure, crying/moaning/etc to a point on getting suicidal thoughts.
- Despite leaving death notes on Shigure's door and saying she will leave him, Mitchan respects Shigure very much.