It's Yume and Mizuto's first summer together as stepsiblings. Their parents are unable to return home one night due to a typhoon. Now alone in the house together, trouble arises when Yume spots a certain creepy crawly in her room. On another day, Mizuto accompanies Yume clothes shopping for a swimsuit in preparation for an upcoming family trip to the countryside. It's in situations like these that the two seem to be finding themselves reminiscing about the past more and more...
The fact that we broke up and the 
fact that we became stepsiblings...
...إنّ حقيقة انفصالنا وحقيقة أنّنا صرنا أخوين
Dass wir uns getrennt haben
und Geschwister geworden sind –
Rompimos y nos convertimos
en hermanastros.
Rompimos y nos convertimos
en hermanastros.
On a rompu
et on est devenus frère et sœur.
Il fatto che ci siamo lasciati
O nosso término e o fato
de que agora somos meios-irmãos...
Наше расставание
и наша новая семья.