Supernova wa Kiss no Mae ni

Synopsis

In an unexpected turn of events, Toki, a high school boy, started dating Fumi Munetsugu, the school's superheroine. After hitting it off to a good start, they faced the next hurdle in the path of romance: a kiss. Completely out of his element, Toki was unable to go for it. The fate of the world, however, depended on it... (Source: LINE, translated)