One day, an egg was brought from nowhere. By chance, he is dropped at the front door of Yasumori Mishiba's (Miho) house. With the school festival approaching, he was considering a program with only four members. Miho wonders if this egg can be used as a centerpiece. However, the egg gave birth to a "pony", a small creature with the legs and tail of a horse and a human-like upper body. A school comedy about a new species of creature, the Pony. "Where did Pony come from?"