Confirmed now..latest vlive of Jihoon said he approached Sunwoo in Inkigayo and ask if he really asked Sunwoo if he already have company. Because Jihoon cant remember already. Hihi
Jihoon (treasure) and Seunghun (cix) were in the same class (applied music) but they droped out from school. Sunwoo was also in applied music, maybe they were in the same class with them and one of them is maybe the one. And Chan from To1 maybe.
There is a chance that it could be Jihoon because Sunwoo said "jigeum" which means now. If he said "geuttaeneun" which means back then, that's when it would have been different. Well, I do wish they are friends because it's always good to see the idols interacting.
Wait.. Let me connect the dot. So Park Jihoon from Treasure also 00 liner from Hanlim. He was a class president too. But drop out because he want to focus on training. Jihoon friend with bomin golcha. So i think, its Jihoon
I think it's Jihoon bc they were in the 7th class at the same time in Practical Music (Sunwoo told that in his Vlive with Eric & Jihoon too) + they are both Bomin's high school friends.