Kono Minikuku mo Utsukushii Sekai, Tenchi Muyou! Ryououki Recommendations
Both animes involve a seemingly-average Japanese high school boy who stumbles upon at least one or more beautiful girls from outer space. Through this encounter the hero unlocks his own supernatural powers in order to protect his ever-growing household of family, friends, and prospective girlfriends (human and alien alike). Teen romance (and all its awkward funniness), love triangles, hotsprings, and sci-fi action for a good measure.