|Voice Actor||Mizuhashi Kaori|
Kotomi Komiyama (小宮山 琴美 Komiyama Kotomi?) is Tomoko and Yū's classmate in middle school, who appears in the spin-off manga. She and Tomoko do not like each other very much and are usually forced to get along with each other when Yū is around. She is later revealed in the main manga to have gone to the same high school as Tomoko, though Tomoko had more or less completely forgotten about her by then. She has a crush on Tomoki, but Tomoko had more or less squandered her chances of being with him.
Yū ends up befriending Kotomi in middle school on a day when Tomoko had to stay home due to fever.
Kotomi holds a deep seethed grudge against Tomoko, considering her a bitch and human trash. The two share a common anime interest but this doesn't bring the two closer as Tomoko openly laments that only kids watch cartoons. It is later revealed that the two of them ended up attending the same high school. Tomoko doesn't remember Kotomi at all though, further angering her former classmate.
- "People should recognize that some girls are just nipples and nothing else."
- "That fucking bitch! She's trash, just like I thought!!"