|Anime Debut||Episode 6|
|Japanese Seiyuu||Haruka Tomatsu|
|English Seiyuu||Emily Neves|
Despite her gentle and sweet outward demeanor, she is interested in Junpei mainly because of his misfortunes, and can be considered sadistic, delusional, and an obsessive stalker. In the anime, she is shown to have this sort of behavior even at a young age towards one of her teachers. She also shows her jealousy if another girl gets too close to Junpei.
Kotone is a person who is attracted to people with misfortune in their lives, such as Junpei. She is a stalker when it comes to Junpei and has a possessive, possibly even lustful love for him. She is more open about her feelings than her sister Akari and expresses herself through unconventional means.
Also, she seems to be more at ease than her sister but this is because of her calmness. She cares about her sister but does not want her to intrude in her life to the extent of getting Junpei away from her.