Tenchi Muyo! War on Geminar is a oVA anime that premiered in spring 2009, produced by AIC Spirits.

About the production: the story comes from an original script, there are 13 episodes of about 45 minutes and its current status is "finished".

Its main genres are action, comedy, ecchi, fantasy and mecha, with themes such as Isekai, Female Harem, School and Super Robot.

On AniList, Tenchi Muyo! War on Geminar has an average score of 73%, a good score, and appears on 41,330 users' lists.

Kenshi —half-brother of intergalactic hero Tenchi Masaki— has been summoned to the mysterious world of Geminar, and his only hope of returning to Earth is piloting a bio-mechanical weapon in a shocking assassination attempt! When the mission fails and Kenshi is captured, he discovers he's been lied to by the very culprits who transported him to this strange new world. Luckily, Princess Lashara kindly welcomes Kenshi and invites him to live amongst her followers. Now, caught up in a political whirlwind —and hotly pursued by Geminar's female population— Kenshi must find a way to get home while civil war erupts all around him! (Source: FUNimation)

Official synopsis from AniList.