While Harada was a bit of a bantamweight,I thought he would fit super flyweight too because he's kinda small at bantam, it's an interesting matchup.
Harada won a world title at Flyweight too. The Harada that took the Fly title from Kingpetch would have been a formidable Super Fly, if not quite the brilliant boxer he would become at BW. There's too many unknown variables in time machine matches for me to make a meaningful prediction with confidence, but Harada certainly beat greater fighters than those Wantanabe beat.
I think he’s a bit bigger, bit stronger, bit better at everything but Jiro wouldn’t look bad in the fight but he would definitely lose to Mr Harada.