While taking their usual bath, the boys discuss how much Kyotaro is like an old man. The next day, when they go to school, they find themselves exhausted by climbing up the stairs... and learn that they're all becoming old men!
What's the big deal? 
It's not that different from how we were.
ليس بالأمر الجلل. هذا لا يختلف
عمّا كنّا عليه
¿Qué importa?
No es tan diferente de antes.
¿Qué importa?
No es tan diferente de antes.
Qual è il problema?
Non è così diverso da com'eravamo.
E daí? Não é tão diferente do que estávamos.
А что такого? Мы
не слишком-то и изменились.