Minami Kuramitsu is the head of the Kuramitsu family—one of the most influential clans in the Galaxy Police—and grandfather to Mihoshi and Misao. He's best known for being overprotective of his granddaughter and, well, nearly destroying Earth because of it.
The Kuramitsu family dominates both their home planet Seniwa and the Galaxy Police itself. Minami's authority is significant enough that his potential anger is a genuine concern for other officers.
He first showed up briefly in the original OVA to report that the criminal Kagato had resurfaced. When command realized Mihoshi was the closest available officer, her superior Nobeyama immediately tried—unsuccessfully—to keep her from engaging with him, specifically worried about how Minami would react if his granddaughter got hurt.
By the third OVA series, things escalate dramatically. After receiving a doctored letter from Z claiming Tenchi Masaki was abusing Mihoshi, Minami didn't hesitate. He sent his younger son Misao on the Choubimaru, an enormous family warship, with orders to rescue her and destroy Earth in the process. He pushed forward despite warnings from military officer Nakita, who pointed out that obliterating an undeveloped planet would violate protocols. Nakita also relayed a threat from Minami's sister Mikami: she'd sell off one of his prized gardening planets to Lady Seto if the ship got damaged. That got his attention.
The fallout came during the tribunal in the final OVA episode. Mikami, serving as judge, demoted him to Head of Maintenance at the Galaxy Police dock as punishment. When Misao later announced his engagement to his assistant Mashisu Makibi, Minami initially objected—until his wife Mitoto surprisingly backed the match and secured council approval.
He's made cameo appearances in Tenchi Muyo! GXP as well, welcoming Seina Yamada to the force and having his maintenance crew service Seina's ship the Kamidake on occasion.
Content compiled by AnimeList.moe from publicly available sources.