Ikumi's childhood friend Mana has a father who's a scientist and inventor. One night Ikumi goes to his laboratory to check on him for Mana's sake and is accidentally caught in the Ai Mai Mist. The Ai Mai Mist changes him into a girl.

While Mana's father searches for a cure Ikumi lives with Mana who watches over her. Adjusting to life as a girl will she want to remain that way forever or change back into a boy? Will she date other girls or fall in love with a boy? The future contains many possibilities.