Aoi Tendo is a young man whose throws are so strong that they pierce the wall. Aoi's goal is to catch up to Shingo Ouki, who set the all-time Koshien record by hitting twenty-four consecutive home runs off the field. Ouki's home rund sequences were against Yu Tendo, Aoi's brother, who died of cancer shortly after Koshien. Unfortunately, Aoi is a lot like his brother, making throws that are so strong that there is no catcher who can handle them, which equates to Aoi being a one-winged bird (as Ouki calls him). However, Aoi meets a boy named Ai who asked to be his catcher. Ai has never had the chance...