The Samurai

Sixteen-year-old high school student Takeshi Chimatsuri has devoted his life to being a master samurai like his father was. Then one day, the Toki twins, two ninja sisters he's known since childhood, transfer to his school and issue him a challenge to take back their family dagger from him. Unfortunately for him, they have discovered his one weakness: the fear of the naked female body. Now, Takeshi must undergo special training from his classmates Atsuko and Torai, and his teacher Miss Ayatsugi to resist the combined brute strength of Akari and the temptation of her sex-crazed twin Kagiri. Class will never be in order with these three constantly fighting each other.
(Source: Anime News Network)