In this chapter, we learn that ikuto is going to die if he does not do something. He wakes up in the middle of the night with a purple violin in his hand. He decides to go to the amusement park and apologize to his friend, but he also wants to do something for the sake of his brother, who has lost his soccer ball. He tells his friend that if he can create happiness for one person in the world, he will be able to create happiness in the entire world. The narrator tells us that this is the first time we've heard of this idea of creating happiness for a single person.