Unforgettables

Cool guy got hit by a vehicle, his soul transfers to one of the most bullied guys on earth. In the latter's school, he met his childhood friend, who in turn started to get suspicious.

NOT YAOI. Dice- it can change anything... your appearance, your brains, your brawn. Sometimes, just by completing a few simple tasks, sometimes, you have to kill for it.

Handsome Guy x Ugly Guy plus a handful of equally lovely side pairs. Awkwardness, second-hand embarrassment, you'll get it all along with a sure dose of crying while laughing.

Yeon-ho's friend, Jae-ha, died on their high school graduation day. Ten years later, Yeon-ho moved back to his old hometown, coincidentally, living in Jae-ha's family's old home. He then found a secret, boarded-off room which contained a drawing book and a telephone. This telephone turned out to be a portal to the past where he could talk to a young Jae-ha, who was still alive.

The premise is a bit of a trope already but this manhwa is still quite touching.