After Miyagawa Utaro was discharged from the hospital, he found a blue notebook with his own handwriting, but he had no memory of the contents. Later, he met Yabe, who sold his brain. Yabe claimed that he provided Miyagawa's brain, which caused Miyagawa's personality to change. Miyagawa is eager to see the Y mentioned in the notebook, and consults the doctor to no avail. He also met Yabe's lover Mieko. In order to gain Mieko's love, he asked the doctor to operate again and transplant part of Yabe's brain. Will the operation be successful? Can Miyagawa get rid of the troubles in his heart? What will be the future between him and Mieko?
