Young Days Summer has arrived for Natsume and his friends in the school. After exams, Natsume, Sasada, Nishimura and Kitamoto go on a trip to an art museum. Upon his return, Tohko reminisces about an old friend that she felt she'd wronged, this makes Natsume think back to his own turbulent childhood. In the present day, a youkai living in the branches of a tree thinks back to Natsume. She had been bored because no one could see her, and when she found out that Natsume could see youkai, she often scared him to be noticed. Both of them parted ways on bad terms. The story returns to Natsume in the present day, who makes a stop at his old neighborhood to visit her. The yokai, who had isolated herself from humans, is relieved to see that Natsume is okay and has found a reason to smile now.