|Name in Japanese||永澄の父|
|Rōmaji Translation||Nagasumi no Chichi|
|Debut (Anime)||Episode 01|
|Voice Actor (Japanese)||Atsushi Imaruoka|
|Voice Actor (English)||Andy Mullins|
Nagasumi's father is a tall, muscular man with short black hair which is similar to Nagasumi's, and has black eyes. He is often seen wearing a solid tan green short with short pants and slippers.
Nagasumi's father is overprotective of Nagasumi and has a deep hatred towards Sun Seto. Upon his wife proposing the ultimatum marriage Nagasumi's father disapproved of her to which therefore that he went to try and attempt to kill Sun and he did not change his views on her. Nagasumi's father is Sun's biggest threat to her survival. It takes little to provoke him and even send him on a blind rage when it comes to his son when it revolves girls being around Nagasumi. Their are instances where his love for his son take rather unpredictable and insane turns. Nagasumi marrying Sun is as he sees it, Sun stealing Nagasumi away from him. He doesn't show any aggression or grudge toward Maki. He warns the other female charcaters including Lunar if they even think about doing something with Nagasumi he will do something to them which leaves them very scared and fearfully walk away.