Kimi to Hanabi to Yakusoku to

Makoto Natsume, a first-year junior high school student in Chōfu, Tokyo, is suddenly confessed to by a fellow freshman named Aki Hayama. Aki told him that her grandmother once told her about meeting a boy named Makoto Natsume in the future. Having never met before, Makoto is convinced that Aki is mistaken. When Aki brings up a painting of a fireworks, Makoto decides to help her find the Makoto Natsume she is looking for. The following year, the two head to Nagaoka, Niigata, to attend the city's famed fireworks festival, suspecting that the painting is linked to it.

(Source: Wikipedia)