Every year, it's my custom to visit my grandparents' house at the end of summer vacation. However, this year I didn't feel like it. --Because my "Big Brother" is gone. * I hear a voice calling out "Chi-chan." But only "Big Brother" calls me that. Big Brother is not my real big brother, but he is very kind, strong, warm, and I love him. He must be somewhere. I decided to head to his house to look for clues about my big brother.