Manga by author Shiozaki Yuji - Status completed

Kamiwazumi Jun lives alone in an old house with a shrine. As a result, people sometimes leave random things outside his house, like kittens... or an unconscious naked girl?! The woman in question claims to be a robot from the future who has come back in time to protect Jun, the future messiah. She has no qualms about nudity, and retrieves useful objects from a "9th dimensional pocket" between her legs. Once Jun has accepted that her story must be true, he also has to figure out how to work a sexy robot girl into his everyday life, which also includes explaining her to a cute childhood friend that has a crush on him.

From Tokyopop:When freshman transfer Mokichi arrives at Swan Academy High, he's got a chance to start over with a clean slate. He's got a plan, too. Kick the butts of the toughest guys in school, prove himself to be the baddest dude around, and run the whole shebang. Problem is, it's his butt that gets kicked that first day. Completely humiliated, Mokichi joins the Wrestling Club in hopes of learning to fight. There he meets unlikely allies, Tamako and Higuchi, two of the hottest battle babes to ever roll their sweaty bods over Swan Academy's gym mats. And Mokichi's gonna need all the friends he can get, what with the likes of the Karate Club looking to "break in" the new kid in the worst way possible.