Leo is called a genius in using basic magic spells. But he is still learning the spells for monster capturing and he can't even tame weak monsters yet.One day he meets with a monster girl 'Captain Vanilla' and she teleports him to a mysterious island saying this will help him master his magic.
This island is taken over by Baron Squid and turned it into his personal paradise. Now he is abducting monster girls from all over the world to chose one to be his wife. Confined to this island with the angry humiliated monster girls Leo with his ability to capture monsters decides to trust his mastery in basic spells and lead the monster girls to fight against the squids.