Zaitsu (座逸) is a student of Sankai High, and a member of the Folk Song Club.
A week ago prior to the end of summer vacation, he received a phone call from Masami Sada, who asked him to meet her at a park so she can return him the music sheet she borrowed. However, while working his part-time shift, one bad thing happened after another, which caused him to be late and she had left by the time he arrived. He got worried, as he hoped to give something to her, and as he got lost in thoughts, the spirit of a cicada, who lingered because 7-10 days of love was too short for it and so rejected death, came to possess him, as their souls resonated in sympathy.
The cicada would then sing loudly about “Seven days of Love”, using Zaitsu’s skill in guitar, and the students can hardly stand its rattling sound. Rinne was sought by members of the Folk Song Club, and he uses a spirit sedative to extract the cicada from Zaitsu, who reveals his regret to have not met Masami in time and gives her what he hoped to give her: a love song recorded on a CD. The cicada however struggled while coming off of Zaitsu, but Rinne, Sakura and Tsubasa points him that its girlfriend named Yumi obviously passed on, so it lets go of Zaitsu and passes on.