Migi and Dali have been fully accepted as members of the Sonoyama family.
They behave just like real parent and child, but the twins notice that Mom and Dad are acting somewhat distant.
Suspecting that the Sonoyama couple might be hiding something, the two discreetly begin to search the house and stumble upon an unexpected secret of the couple.

Migi and Dali are shocked, wondering if they have been deceived. However, determined not to let things end this way, they execute a plan to retaliate against the Sonoyamas.
We have to
.علينا أن نحرص ألا يعرف بشأن حفلة الترحيب
Hitori no debe enterarse
antes de la fiesta de bienvenida.
Hitori no debe enterarse
antes de la fiesta de bienvenida.
Hitori ne doit rien découvrir
avant sa fête de bienvenue.
Dobbiamo fare in modo che Hitori
non la scopra fino alla festa di benvenuto.
Temos que tomar cuidado pro Hitori
não achar antes da festa de boas-vindas.
Нельзя, чтобы Хитори узнал о сюрпризе
до приветственной вечеринки.