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!
You've gotten so round...
...أصبحت مدوّراً
Du bist so rund geworden …
te has hecho tan redondo…
te has vuelto tan redondo…
tu es devenu si rond…
Sei diventato così rotondo...
Você ficou tão redondo...
Ты теперь такой твёрдый...