Asu no Yoichi!

Yoichi Karasuma has mastered the sword after spending all seventeen years of his life training with his father in the mountains. His father decides that what Yoichi lacks now is not combat skill, but experience with people and the modern world, and sends him to continue training at the Ikaruga family dojo in the city. There, Yoichi moves in with four sisters who are unlike anyone he has ever known. He speaks like a samurai from another age, understands almost nothing about everyday technology or social boundaries, and stumbles into one misunderstanding after another. Between rival martial artists and problems no sword can solve, Yoichi discovers that ordinary city life may be the hardest training he has ever faced.