Following the most intense battle of his life, a young man washes up on astrange shore. He is found by a swordswoman named Shizuka Kosugaya and informedthat his name is Kojou Akatsuki, and that he is the fourth vampire primogenitor.In the days spent healing his mind and body, the two encounter a third person: Abeautiful girl wielding a silver spear that calls Kojou..."Senpai."