Minami Kuramitsu is the son of Mikumo Kuramitsu and Miyuki, the brother of Mikami Kuramitsu, the father of Mitoto, the grandfather of Mihoshi and Misao, as well as the grandson of Washu Hakubi, Ranma and Nabiki Kuramitsu and the Grand Marshall of the Galaxy Police. The Kuramitsu family is one of the most powerful families on the planet Seniwa, and is very dominant in the Galaxy Police.
Due to his high strung nature Minami is considered somewhat of a black sheep of the Kuramitsu family. Minami reported to the GP commander that the criminal Kagato had returned. After that the commander found the only officer close by is the Marshall's granddaughter Mihoshi, much to his dismay. Her superior officer Nobeyama then tried unsuccessfully to tell her to not to engage Kagato, to avoid the Marshall's wrath if he were to find out that Mihoshi were in danger.
Minami loves his granddaughter greatly, so much so that when he received a letter (altered by Z), saying that she was being abused by Tenchi, Minami quickly dispatched her younger brother Misao aboard the Choubimaru, a huge ship owned by the Kuramitsu family, to rescue Mihoshi, and destroy the Earth to kill Tenchi. Minami went through with this plan, despite a warning from the military officer Nakita, that since the Earth is an undeveloped world, he would risk having the Earthlings see it. Nakita also delivered a message from Minami's sister Mikami, that she will sell one of his gardening planets to Lady Seto should the Choubimaru be damaged in the attack, much to Minami's dismay.
During the meeting to pass judgement on those involved in the Choubimaru incident, by Mikami's judgement, Minami is demoted to the position of the head of maintenance at the G.P. spaceship dock as his punishment. When Misao had decided to marry his assistant Mashisu, at first Minami protested that she was unworthy of marrying into the Kuramitsu family, but was shocked when Mitoto had announced her support and that she was able to get the family council’s approval for the wedding.