Kemeko Deluxe - HentaiMovieRealm

The high-school student Sanpeita dreamed he was engaged to a beautiful girl. Then one morning, a strange homely girl suddenly breaks through a wall in his bedroom to tell him that she is his bride and that her name is Kemeko. In order to escape, Sanpeita fled his house and went to school, but Kemeko follows. And things got only stranger when Sanpeita was targeted by something that looks like a rice cooker on the school's rooftop. As Sanpeita and his childhood friend Izumi were being attacked, strange little Kemeko intervenes to save them both. Just who is Kemeko? Someone who claims to be Sanpeita's new steel bride!?

Sanpeita is surprised to learn that Kemeko is really a girl-style powered-combat-suit and that the pilot is a cute girl. A heavily armed and violent girl perhaps, but still very cute.