Damn, I wasn't expecting it to turn out this well. I was already anticipating tons of more drama, but he went in for the kill
Now we just have to avoid the flag of Mia seeing them kissing through the door/binoculars/the hidden camera she set in that room/the glass ball that shows you what you want to see the most/etc. If we avoid that flag, at least we avoid heavy drama for quite a few chapters.
If we don't avoid it... we in for a ride

We could still be in for a wild ride even if this situation turns out well. Mia have choppy memories doesn't bode well. Seojin (the pretty and tall girl from chapter 34 MC bumps into, also the friend(?) who called Mia some chapters back) probably heavily influenced her and probably helped her. Now MC just has to find out Seojin knows Mia, convince Seojin to spill the beans and then we will know what tf happened to Mia during those years and why her memories are choppy. Did she have an accident? Did someone hit her head with a bat? Was she so depressed/overwhelmed she forgot a bunch of things? Could be several things.
There is a happy ending in sight, but quite a few bad endings all around as well. Hopefully the author doesn't enjoy making the readers suffer too much
And man, I'm dumb. I only made the connection that the tall girl from chapter 34 was the friend that called Mia before. Even though both times we saw the name "Seojin", I just couldn't make the connection at that time. And heck, the could turn out to be sisters. Anyway, I hope we see her more often.