10 years ago as a little girl, her grandfather promised to win her a teddy bear at a shooting gallery game at the summer festival, although what she really wanted was the fashion set next to it, but he died three days later. His spirit remained, as he was filled with regret for failing to win the teddy bear, and he would stalk her year after year when she goes to the summer festival, make the teddy bear appear at the shooting gallery game and make her boyfriend try to win it although he would not allow him to win it in his place.
Believing she is cursed and wishing to be freed of it, she enlisted Rinne’s help, asking him to go to the summer festival as a couple to find the root of that curse. There, Rinne could see the spirit of her grandfather and resolved his irrationality. After seeing her grandfather pass on, she kept the teddy bear as a keepsake and joined her boyfriend.
- "Natsumi" can be written to mean "summer beauty" (夏美?).