Upon arriving at Sunshine School, transfer student Aoba Shunsuke found the campus completely empty. Despite the fact that it was a rest day for the institution in celebration of Foundation Day, Shunsuke was secretly thrilled to be the first one there. However, his excitement was short-lived when a stunningly beautiful girl named Natsumi, who went by the nickname "L" or Eru, appeared before him. Despite their height difference, the two hit it off right away.