A Situation About "Living With a Girl Under One Roof"

She's My Maid, Little Sister, Childhood Friend, and Evil Instructor

She's My Maid, Little Sister, Childhood Friend, Evil Instructor, and Classmate

She's my Maid, Little Sister, Childhood Friend, Classmate, and Student Council President

Change of Pace (The Bathroom War)

She's my Maid, Little Sister, Childhood Friend, Classmate, Student Council President, and XXX

The story is about Hayato Heiwajima, an ordinary guy who is the main successor of his grandfather's company, Heiwajima Industries. His maid, who is also his close relative, childhood friend, and demon instructor, is responsible to teach him how to deal with females and not so easily be fooled by others. The problem is that her teaching methods go beyond the ordinary just a "little bit". 