|Debut (Anime)||Episode 10|
|Appears in||Anime, Manga, Game|
|Relatives||Mrs. Kasugano (wife) (deceased), Haruka Kasugano (son), Sora Kasugano (daughter)|
The anime did not reveal much of their background. It is only shown that he and his wife have a beautiful apartment in a certain city.
- Mrs. Kasugano (wife) (deceased)
- Haruka Kasugano (son/son-in-law)
- Sora Kasugano (daughter/daughter-in-law)
- Unnamed/Unborn Kasugano Child (grandchild)
- Parents or in-laws (mentioned in the series)
- Kasugano distant family relatives (mentioned in episode 12)
- His first name is not revealed.
- His family history is not revealed.
- He was unaware that his son lost his virginity at a young age because of a sexual encounter with Nao.
- He was unaware that their son and daughter have fallen in love with each other.
- He was unaware that their son and daughter shared a kiss when they were playing a childhood game.