Seina Yamada starts out as Tenchi's best friend, though his notoriously terrible luck keeps most people at arm's length. His parents run a small grocery store, and aside from Tenchi, Kiriko, and her brother Kai, Seina's basically friendless—disasters just seem to follow him everywhere. That changes when Galaxy Police Detective Amane Kaunaq crash-lands a spaceship at the Masaki place. She meant to recruit Tenchi but accidentally hands Seina a G.P. application instead, mistaking him for someone Tenchi was training. His family literally forces his signature and thumbprint onto the form, hoping he'll win some prize money. Instead, he wakes up on a spaceship as the newest G.P. Academy cadet.
On board, he reconnects with his friend Kiriko, who's already a G.P. officer, and meets Mitoto Kuramitsu, Mihoshi's scatterbrained mom and professional cleaner. He's quickly thrown into the thick of it: stopping the Daluma pirate guild from taking over the galaxy.
The G.P. eventually figures out that Seina's bad luck actually attracts space pirates, so they weaponize it—literally. He gets put in command of a Decoy Fleet ship called the Kamidake, designed by Tenchi's sister Tennyo. When it gets wrecked fighting pirate Tarant Shank, Washu Hakubi builds him a replacement, the Kamidake II. This new ship comes with a cabbit companion named Fuku (similar to Ryo-Ohki but serving as both terminal and power source). Later, under Seto Kamiki Jurai's direction, the ship gets upgraded into a hybrid by fusing it with Kiriko's royal tree Mizuki, giving it Light Hawk Wing protection.
While commanding these ships, Seina earns a fleet commander's salary—money that gets held in trust until he graduates. The interest alone is enough to transform his family's tiny grocery into a sprawling supermarket back on Earth, and they build a massive new house too.
Things get wild when Seina rescues Fuku from rogue Galaxy Army operatives. A Wau tribe mistakes him for their savior and throws him into an ancient mecha that somehow bonds with the Kamidake II and generates Light Hawk Wings on its own. Turns out the mecha's powered by a first-generation Jurai tree seed, and that seed bonds with Seina. Suddenly he's third in line to the Jurai throne, behind Yosho and Tenchi.
Political marriages follow. Seina ends up with Amane, Kiriko, Ryoko Balta, and Neju—except it gets messier when Seto's ladies-in-waiting (actually Renza Federation spies) kidnap and publicly seduce him to protect their organization. He marries all of them in the end: the original four plus the four spies, plus Fuku. Now he commands a crew made entirely of his wives, still patrolling space for pirates and lawbreakers.
Content compiled by AnimeList.moe from publicly available sources.
