Everyone around Futaba expects her to grow up and become an adult, and she's lost the ability to keep herself mentally balanced. At the bottom of her heart, her childish self is still there, and still strong. One day she wanders into another dimension, a world where the light has been lost, and darkness rules. The people there exist as babies wearing only their underpants...
You're the hero who's 
going to save our world!
Du bist die Heldin,
die unsere Welt retten wird!
¡Eres la heroína
que salvará nuestro mundo!
¡Eres la heroína
que salvará nuestro mundo!
Vous êtes le héros
venu sauver notre monde !
Sei l'eroe che salverà il nostro mondo!
Você é a super-heroína
que vai salvar nosso mundo!
Героиня, что спасёт наш мир, явилась!