Choukou Sennin Haruka Vol.1 超昂閃忍ハルカ

Takamaru is a high school student, living a peaceful life with his old friend, Narika. One day, he falls in love with a girl, Haruka. A while later, Takamaru and Narika are suddenly attacked by strangers. And Haruka in a kunoichi (female ninja) costume appears and saves them. Haruka respects him as her master and urges him to have sex with her. Actually, Takamaru is a boss of his ninja troop and has a special ability that he can give a huge battle power through sex. Haruka gets the power from Takamaru and tries to defeat her enemy. But it is just the beginning of a long-lasting war....