Jotaro Aragaki

Jotaro Aragaki (荒垣 城太郎, Aragaki Jōtarō) is a former athlete on the Japanese gymnastics team, the husband of Tomoyo Aragaki and the father of Rei Aragaki.

Appearance
Jotaro is a muscular man with brown eyes and light but tanned skin. He has dark brown hair which he typically wears pulled back into a messy ponytail, a feature that’s given him the nickname “Samurai”.

Personality
Jotaro is a passionate man who tends to push himself past his limits and believes that he can do anything through hard work. His mindset gradually changes as the anime progresses.

Rei Aragaki
Rei is Jotaro’s daughter who have a close relationship. Despite this, Jotaro seems to be unaware of how much his daughter sacrifices for his own benefit as Rei frequently tries to hide things like school events and her own feelings from Jotaro so he can continue working wholeheartedly on gymnastics.

Leonardo
Leo is a friend of Jotaro’s.

Etymology

 * The name Jotaro means "castle" (城) (jo), "thick, big, great" (太) (ta) and "son" (郎) (ro).
 * Jotaro's surname Aragaki means "laid waste, rough, rude, wild" (荒) (ara) and "hedge, fence" (垣) (kaki/gaki).