this may be cheating but -
technically, raijin is in his late 40s? but with a wish from a wish ring, he was placed back in his 20 year old body with like, all his memories and stuff. he's not immortal or anything, and he will now have a completely regular lifespan, but when we started the game he was 45. he was, uh... 47? i wanna say? or 48? when they wished him younger. because all of his spouses are WAY younger than he is, and he wanted to have time with them, esp when his wife got pregnant.
anyway i'd say he's pretty happy! like, personality and stuff wise he's still that older man? he still has that life experience, those memories. he hasn't changed much from past raijin except opening himself up more to new experiences and becoming more comfortable with who he is. he had a bit of a mid-life crises prior to the wish ring but he's p good now! he has him some kiddos, his wife, his husbands. he's chilled out a lot more from the brash youngster he was, i guess?