That was my first thought, too! XD
But I guess when you consider how many bad associations and memories our dramatic Yaetatsu has tied to it, it probably makes more sense to get rid of it... (altho I'm not buying at all Toraji's allegations that he's not jealous at all no sir not him XD)
My very first idea was that it'd be something related to his father, some memento or sth, since he was thinking what to do with his suddenly free time and how he'd turn into his dad if he just nitpicks all the time etc etc
But as you pointed out. We must never underestimate Yaetatsu's ability to turn literally anything into a dramatic source of angst XDD
Thanks for reading and commenting, as always! <3