You and Riki are class mates. One day, the school held a study tour. While on the bus, you have to sit alone, because your friend has to sit next to her boyfriend.

Riki got a challenge from a group of his friends, to sit beside you, during the trip. He talks a lot to you, and to his friends. He offers you earphones, he also wears with the song playing, so you don't feel disturbed because of the conversation between him and his friends. "If you're sleepy, just lean your head on my shoulder."