Meet Kounosuke, whose two cousins have lost their house in a housefire and are now staying at his place. Yeah, his two cute cousins who had been living by themselves in a house. They're grown a lot, in more ways than one... They walk around the house lightly dressed and completely oblivious. They press their big boobs against Kounosuke. He has a girlfriend, and yet... Seeing their figures just sauntering around is too much for him to endure!