Himeka's a shy and quiet girl in Kitagawa Mimi's class. She was often alone by herself and avoided outdoor activities. Seeing that, Mimi decided to help her overcome her personality and enjoy with the class.
However, it turned out that Himeka was also interested in Toujou Ushio. Mimi started to notice Himeka's intimate actions with Toujou and got boiled up emotionally. Himeka then admitted and declared a love war against Mimi.
In the end, it was actually a plot to ruin Mimi's relationship with Toujou because Himeka was jealous that Mimi's such a wonderful and popular girl, even Himeka's ex-boyfriend was falling for her. Himeka apologised to Mimi for her wrongdoings and all were back to good again.
Himeka's fashion sense was still not as expected. She seeked Mimi for advice for a social gathering. However, Himeka accidentally overheard comments from her classmates about her poor dressing after that. This made her very upset and ran away. Mimi decided to help her out again because she felt that it was her fault for not telling Himeka properly on how to dress savvily.