Help me find this manga

I read this story a long ass time ago so the facts may not be 100% accurate but this is the best I can do

>>Its bl
>> The story’s setting is in a school
>> MC 1 founds an extra room in his school, I forgot what kind of room it is
>> MC 1 meets MC 2 in that room
>> They talk n shit ofc they fell in love bcs duh its romance
>> Oh and they also slept together in that room in school

Here’s some v specific details abt said series
>> Apparently MC 2 is from the past
>> MC 1 is from the present- the reason why MC 2 found out is bcs he saw the date in MC 1’s phone
>> After MC 2 found out it they couldn’t go back to the room bcs he found out the secret of the room
>> UHHH I can’t remember exactly what but right after MC 1 and MC 2 slept together, this is the time MC 2 found out abt the different time thingy, MC 1 is alone in that room.

>> MC 2 after him not being able to go back continue to study somewhere

>>MC 2 meets a woman who looked like MC 1

>> MC 2 and thw woman got together and had a kid and named him after MC 1

>> MC 2 realized that after the kid grew up he started to look like MC 1- he realized that the he met was HIS SON AJBZHEHE

>> THE PERSON WHO FOUND MC 1 IN THE SCHOOL ROOM WAS HIS FATHER AKA MC 2

YALLLL THIS IS NOW WAY MORE DETAILED HAHA IF ANY OF YOU KNOWS THIS PLS COMMENT !!!

Basically thats the story? I can’t remember how it ended so if yall know the title of this series pls tell me huhuhu

Its not "Not Equal"-- they were hs students

Last time I'll be postjng this bcs Idk if this sereis can even be found,,, I tried like I spend hours tryingbto look for this..