天地無用！登校無用

With so many beautiful alien girls living in his house and constantly getting into chaotic adventures, it feels like the only peaceful moments Masaki Tenchi has left is when he's at school. That is, until they decide to enroll!
On the same day though, there's a transfer studentー a mysterious blue-haired girl named Tsunami. Although they've only just met, he can't shake the feeling that he knows her from somewhereー who could she possibly be?
At the same time, the "Coquettish Bombers" (a group of three Bounty Hunter girls; Sakaki, Ibara, and Kinoko) are traveling to Earth on the suspicion that the infamous Space Pirate Ryouko is there!
By the time the day is over, will Tenchi's peaceful school life be left standing? Moreover, will his SCHOOL be left standing!?