Six men and women are reunited at a high school reunion. Our heroine Tamaki meets her first love again, which was unrequited, nine years after graduating high school. The next day she wakes up to find she has time-slipped 10 years into the past and is once again a 17-year-old?

A love story of redoing your youth!

The male protagonist Utsumi Shinichi is a well known established 31-year old author but has lost his inspiration and is currently living as a shut-in at his grandmother's house in the countryside all alone without barely taking care of himself. Then one day a 10-year-old girl named Haruka stops by and asks Shinichi for permission to take care of a stray cat in his garden. This young girl causes an unexpected reaction in him and he agrees. Shinichi learns that Haruka is an aloof and introverted girl whose parents are barely home: her father travels a lot and her mother is sick in the hospital. After meeting Haruka, Shinichi's editor Oogaki convinces him to use her as inspiration for a new romance novel. Shinichi isn't interested in Haruka in a romantic way, but he pities her because she reminds him of his tragic child self and his lonely childhood. Eventually, they develop an awkward friendship, and somehow they can't leave each other alone. What is in store for them? Why does the laidback Shinichi react this way to this young girl?