You're on the right track.
Spoiler me pls
Spoiler
MC is in year long comma and misses the deadline to claim the ticket, during the car crash that lands him in hospital he gets iseakaied to the past with ML(their wishes got mixed or something), ML is fully aware since birth and is 30 going on 18, the plot plots why ML and white haired are fighting (it has nothing to do with MC, but he is the catalyst to their current level of anymosity, it's his looks, but ist's convoluted and I didn't get it that well). More things happen and MC wakes up in the hospital, leaves and meets ML who is now 60 going on 30 and he was waiting and looking for MC. The gay is strong.
To be fair, this would work great as just school life comedy, all the isekaied supernatural stuff wasn't that important or needed, tbh.
His uncle said his hospital bills? Is he in coma or smth