In a flooded world, a boy rescues a robotic girl from the sea. Grateful, she vows to be his "leg" until fulfilling her former master's order, leading to an unforgettable summer adventure.

After an explosive encounter with a powerful magic user, Megumin informs her parents that she wants to study explosion magic at the Crimson Demon magic academy called the Red Prison.

A young man with connections to the supernatural rents a room haunted by the ghost of a 16-year-old girl.