小宮山 琴美
from WataMote: No Matter How I Look At It, It's You Guys' Fault I'm Unpopular!
Origin
Japan
Tomoko and Yuu's classmate in middle school, who first appears in the spin-off manga and is later revealed to be attending Tomoko's high school. She and Tomoko outright dislike one another, only pretending to get along when Yuu is around.

WataMote: No Matter How I Look At It, It's You Guys' Fault I'm Unpopular!
Kuroki Tomoko is a super popular, high school girl who has had 50 years of dating experience and 100 boys... in the Otome game world. In the real world, she is a 15-year-old shut in who has all of the qualities of a "mojo" (a gloomy or unpopular woman). However, when school isn't going as she expected, and she isn't as popular as she had thought she was, she takes a look at herself in the mirror for the first time in a few years, and has some shocking revelations...