After getting Natsuki hurt when a small dog barks at them, Ryoku questions if he is useless to Natsuki and gets depressed. Moping by himself, Ryoku finds a partitioning screen in Natsuki`s house which has a powerful dragon and a tiger drawn on it. According to Natsuki`s grandfather, the dragon and tiger are said to have been rivals, fighting for the position of the strongest in the world since olden times. Hearing that, Ryoku is determined to become a powerful dragon that can protect Natsuki and begins to train. However, the next day, upon hearing a loud noise from the room with the screen, they take a look and find a huge hole where the tiger was. Natsuki and Ryoku both find this strange. Truth is, there is a legend that the tiger drawn on the screen sometimes jumps from the screen and prowls around.