Help me

Hi can anyone help me finding this bl name it been a long time since I read this bl manhwa and Im kinda forget it.

I don't exactly remember the story but it took place in highschool . I don't really remember the mc but if I'm not mistaken it might be the top. One thing for sure it's like there's a timer on the sky that only he can see. It like he need to falling in love with someone before the timer end or else he die ( if I not mistaken the plot is like this but ya like I said it been a forever since I read this) . Physically the top is like black hair and have tan skin(?) and the bottom is like blonde hair. But I remember there's this side character he have blonde hair and very close to bot and they have matching keychain that look like cat?. Ya that all I can remember

I would really appreciate if anyone can help me. I really want to reread it again.