there's a good story similar to this one called "The man in the mirror"
https://www.mangago.zone/read-manga/the_man_in_the_mirror/
the concept is almost the same except in this they can actually enter the mirror and visit each other's places
it's also finished and quite adorable
someone already mentioned this in another comments but the story feels like a bit like a wattpad/fanfic and that's kind of accurate, the FL is all like "how could it possibly be okay for me to be near him?, in his presence? he's the emperor and he's so handsome to boot. I'm just the royal sibling's tutor (︶︿︶)" which makes their interactions sort of forced and awkward
then theres the art which isn't necessarily AWFUL but if you're a manhwa veteran then you KNOW that the art is MID quality at best compared to other works
HOWEVER, I have to add that I might be biased regarding that since I'm an artist and I tend to be more picky about that sort of stuff (mind you, I'm not claming to be freaking leonardo da vinci)
bro like, sawami is my whole ass type (only missing tattooes) but seriously
his vibe, that height, his fashion sense, THE JEWERLY
seriously man really sleep on jewelry when done correctly it's SO ATTRACTIVE
give me your funniest man/wha/ga/hua screenshots RIGHT NOW i need laughter
I feel so lost rn and maybe I'm just forgetting something (I'm gonna have to reread the whole thing and it's so frustrating)
but I swear I remember the lybrarian teacher mentioning something along the lines of "things written in destiny/fate are impossible to change" and that hanako managed to do so when he died but that that incident in itself was a taboo (I think he also mentioned that's the reason hanako became a supernatural but I'm probably imagening that)
now we're being told that the clock keepers could have changed the sequence of events anytime they wanted to simply by tweaking something in the timeline
I HAVEN'T SCREAMED SO HARD IN MY LIFE WHEN I FINALLY READ THE WORDS "I LOVE YOU" FROM HIM, AND NOW WE GOTTA WAAAAAIITTTTTTT!!!?????
THIS IS DOWNRIGHT CRIMINAL