The three maidens Mayuka, Izumi and Usagi have the ability to repair mechanisms in a rather unusual way (which is kept a closely guarded secret). They put on them a pendant in the shape of a banana, after which the reproductive organs grow from the broken object. The girls satisfy the piece of iron, and it is miraculously "healed". The main character learns about this ability and blackmails the girls: sex or publicity. The anime tells about one of their adventures