Kukuru's grandfather directs Gama Gama Aquarium, a small, aging facility burdened by financial struggles and maintenance issues. He assumed leadership without prior management experience yet sustained operations for many years despite persistent monetary challenges. Recognizing the aquarium's unsustainable state, he pragmatically plans its closure, contrasting with granddaughter Kukuru's determination to save it.

He gently encourages Kukuru to accept reality while supporting her revitalization efforts during Gama Gama's final months, suggesting staff downtime and participating in strategic discussions. Having raised Kukuru after her parents' early deaths, the aquarium holds cherished family memories connected to her parents and an unborn sister.

Following Gama Gama's permanent closure due to storm damage, he leverages professional connections to secure positions for displaced staff at the modern Tingarla Aquarium. His acquaintance with Tingarla's director, Akira Hoshino, facilitates this transition. He specifically arranges Kukuru's placement in Tingarla's marketing department, not animal care, implying a strategy to broaden her skills for future roles.

Deeply knowledgeable about aquarium management and interpersonal dynamics, his insights are sometimes overlooked until critical moments. Physical details include his frequent use of a back massager. His legacy lies in guiding Kukuru through loss and adaptation, preparing her for life beyond Gama Gama's walls.