Mizuki had a crush on Akihisa since they were in elementary school. After getting into Class F, she decided to pursue Akihisa, but doesn't have the courage to confess and is disappointed in the fact that he hasn't realized her feelings, though he seems to share those feelings with her unknown to Mizuki. Mizuki cooks meals for Akihisa, being unaware that her food is poisonous, and also enjoys Akihisa crossdressing. Mizuki sometimes fears that Akihisa may be a homosexual and is willing to punish him if she believes he is getting to close to another female or male, but otherwise, gets along with him as one of his closest friends. However, she will get angry and punish Akihisa when he is implied to be involved with another girl.
Minami is Mizuki's best friend and rival for Akihisa's attention. As the only two girls in Class F, they get along very well and confide in each other and work together to get Akihisa into women's clothing.While they are rivals, they also do not wish to hurt each other and truly care for each other, though she is jealous of the fact that Minami is able to talk so casually to Akihisa.
Yuuji is a confident for Mizuki on her feelings for Akihisa, and while Yuuji tries to help her when he can, he is also willing to use her feelings for Akihisa to motivate her into doing her best at whatever they are doing. He also seems to care about her enough that he would eat her poisonous cooking rather than hurt her feelings and tell her that she's a horrible cook. At times, Mizuki does wonder if Yuuji and Akihisa are in a relationship and can view Yuuji as a threat.
Mizuki is a common victim of Muttsulini's perverted tendencies, though he does seem to care about her enough that he would rather eat her poisonous cooking than hurt her feelings and tell her that she's a horrible cook. Mizuki is also one of his customers and buys pictures of Akihisa crossdressing off of him.
Mizuki treats Hideyoshi as a female at times, but their relationship as classmates seems fine for the most part, though she does get jealous of Hideyoshi for his looks and slim figure and how Akihisa seems attracted to him. Hideyoshi cares enough about her that he would rather eat her poisonous cooking that hurt her feelings and tell her that she's a horrible cook.
Mizuki is respected by Hazuki after she gave her a doll she wanted. Hazuki calls her "Kirei no Onee-chan" (Ms. Pretty in the English dub of the anime).
Mizuki looks up to Shouko and thinks of her as role model, wishing that she had a similar relationship with Akihisa that she has with Yuuji.
Mizuki is commonly wanted by Class F as one of its few females, and the FFF Inquisition will punish any male that gets too close to Mizuki.
Mizuki looks up to Akira and hopes to get her approval in dating Akihisa. It is because of Akihisa getting used to Akira's bad cooking that he was able to gain some resistance to Mizuki's horrible cooking.