Ayanokouji Kiyotaka, tired and exhausted of his sick father's constant orders, decided to head out for a drink for the first time and met a well-known person in that certain bar. Things went well, talking and such until they get even more intimate as time passes. And at the end of the night, they found themselves in a hotel kissing each other passionately--grabbing and holding on to each others' bodies as if their lives depends on it. And about two months later, they met each other once again. But this time, in a hospital. (I'm borrowing the characters of @Mommy_Eugen since I can't think of any other names. And some characters from Oshi no Ko wouldn't be starring since I still hadn't started reading the manga.) Perhaps, you guys can also say it's inspired from The Girl Next Door.