King's Proposal, Vol. 1 (light novel)

Saika Kuozaki is an all-powerful witch with looks to die for. Shesalso the only woman who can thwart the mysterious entities attempting todestroy the world once every 300 hours. When Saika is mortally wounded,however, she bequeaths both her powers and body to the normal high school boywho happens upon her, Mushiki Kuga. But just because Mushiki has herabilities doesnt mean he can control them. To stand a chance of savingthe world, hell have to attend an academy for mages as Saikaallwhile keeping his identity under wraps!