Running Into You on a Cold Summer follows the story of Yuki Takemoto, a high school student who is no stranger to the ordinary rhythms of his life until he unexpectedly ends up at a friend’s house one summer evening. There, he meets Shiori Izumi, a girl he's only just started talking to. What was supposed to be a casual hangout soon takes an unexpected turn as the evening spirals into a series of awkward encounters, shared moments, and miscommunications.