Seina Yamada has been waiting so long to return to his home, Earth.
But so much has changed; his sister is engaged to Kiriko's brother Kai,
and his parents' old store is now a huge mall.
Furthermore, he is to stay at Kiriko's mother's house...
Son trade?
تجارة أبنائهما؟
S-Söhnetausch?
¿Un intercambio de hijos?
¿Un intercambio de hijos?
Un échange ?
S-Si sono scambiate i figli?
Troca de filhos?
Обмен сыновьями?..