JRPG where the teenage firebrand protagonist is taken under wing by a wise older mentor figure in… (opens in new tab)

JRPG where the teenage firebrand protagonist is taken under wing by a wise older mentor figure in their twenties, as one does, except the third party member to join is in their thirties and regards both the protagonist and the initial mentor as dumb kids; the fourth is in their forties and thinks the same of the first three; and so forth.