Yojôhan fusuma no urabari: Shinobi hada

Shotaro, the son of a geisha house, is still merely a kid and is often told to spend the night in a room with geisha when the patron of a certain geisha takes over his own room. A precocious lad in the first places, he knows more about sex than many adults. He discovers he is old enough to make women pregnant and so his adventures begin, here, there and everywhere.