I can't really read the 4th kanji on the most right column and I can't find it on the radical board either so I'm just guessing
Found that kanji - It's 立派 (fine, handsome, etc.) which combined with 大人 would mean "full grown adult" or "full adult" anyway. Or so at least I would say.
Yay for 3-years-later confirmation.
Wa...Don't tell me!..And things like that happened.I see, it's like that.I am sorry!
I am sorry!
I am sorry!I wondered how it would turn out at the time.Akagi-san, you believed in Santa-san until what age?I'm also a full adult so, it's ages ago. Akagi-san and Santa Claus