One hot summer day, the 4 girls and Haruko are playing in the pool. They notice that Pets is missing. Kana later hears from her classmate Aida that Pet's family is very rich and they are moving to Mars. 
No one does anything for someone else.
Niemand macht etwas für andere.
Jeder handelt nur für sich selbst.
Lo que hacemos por otros,
Lo que hacemos por los demás,
Nessuno fa qualcosa per qualcun altro.
Ninguém faz nada pelos outros.
É tudo só por si mesmo.
Никто ничего не делает ради других.
Всё всегда ради себя.