Haru's grandfather (whose real name is unknown) is Haru's only living relative after Haru's parents died from a bug attack. He works along side Haru at the Four Seasons.
Haru's grandfather wears a traditional Japanese outfit and has no hair.
Haru's grandfather seems to be a warm loving grandfather to his granddaughter and teases her when she has feelings for Jinbei.
Not much is known about his past but after Haru's parents died, he looks after Haru and the family business.
Haru's grandfather, being an ordinary human, possesses no superhuman abilities.