Hikari Kongou
, 金剛 ヒカリ
The young girl is a brilliant student at high school, but she tends to be reserved. She has a close bond with Taihei, who she refers to as her "big brother," even though they are not related by blood. Occasionally, she visits their home for meals.
Spoilers:
She is one of the few people aware that Umaru and Komaru are the same person, alongside Taihei and Umaru herself.
