Ojii

[Kukuru's](https://anilist.co/character/204495/Kukuru-Misakino) grandfather, the head of the Gama Gama Aquarium. He entrusts the day-to-day business of the aquarium to Kukuru during summer vacation, as he goes around on important business for the aquarium. He has a bright and kind personality.

(Source: Anime News Network)