Gate In! summary:
Winter sound, autumn sound, summer sound. A new racehorse is born on the farm of three sisters who love horse racing and racehorses. The three sisters dreamed of winning the Japan Derby with the racehorse they named "Shikio." Time passes and Fuyune becomes a trainer. Akine is the farm manager. And Natsune became a jockey, pursuing her dream for her beloved horse. However, the important thing is that Shikio is living a stale life as a ``racehorse who has given up on winning''. The horse racing story begins with the three sisters pursuing their dreams!!