Hikari Kongou is the younger sister of Kanau and is a character in the Himouto Umaru chan series. She has white hair and eyebrows and is very small. she usually wears her school uniform (almost the same as Umaru's) but the sleeves are a bit to long so they flop around a bit. She likes Taihei to the point of calling him onii-chan (japanese for brother) and when she was younger he used to teach her about the constellations and she remembers them all. She dislike Umaru and fights with her for Taihei's attention but Taihei is completely oblivious and when he finds them fighting he said 'I thought you two were good friends' and after Hikari confesses that she just wanted to eat bread with Taihei everything calms down. She is in the AP classes or gifted classes and is in a separate building from everyone else as the AP classrooms are in another building and her debut was when she was receiving an award on stage along with Umaru. When she is wary and suspicious of others her eyes lose all colour and go white but they still have the lines of detail.