Older teens, ages 16+. Did the aunt mention that Sunako needs to get good grades, too? Sunako must achieve an average above 80 percent, or the deal's off. No problem! Sunako scores high in all subjects--except math, which she consistently fails miserably. Now the guys have to tutor their reluctant student through hours of course work, avoiding the pitfalls of her gruesome hobbies, explosive nosebleeds, and the tendency to faint whenever anybody referes to her kiss with Kyohei. Math would be easier without so much division!