y/n, because she liked mark for so long, got jealous and told his girlfriend that he cheated. mark had confronted his girlfriend, only for his girlfriend to get confused and tell mark where she got the information. mark got angry and came over—by walking, since they live close—to yell at y/n.

angrily, y/n confessed on the spot, motivated by the bad habits mark's girlfriend introduced him to. but mark said he has no feelings for y/n, and he didn't—not anymore. they argued and yelled dumb stuff they didn't mean, but the damage is done: they're both hurt in a way that feels permanent.

y/n yelled at him, telling him to die on the way home. he took the keys she tossed at him so that he could get home, even though he could've walked. even though they fought, y/n doesn't want him walking in the rain, so she used saying him to get into a car accident to anger him and hurt him with every chance she got.

he took the bait and left, but on his way home, his goal was to crash the car enough to damage it. he aimed to hit a pole on the sidewalk; enough so that she'd have to pay a good amount.

because of the rain, the car slid, hitting the pole too hard. the impact made the car bounce back and the airbags exploded, along with a fire starting to begin inside the car.

yet, he survived the crash. he got taken to the hospital, and there he stayed, in pain, hoping that y/n would come visit so that he could apologize for wrecking her car and knowing that he hurt her. when they had fought, he dropped his phone during the sudden confession and broke it, so he couldn't contact her. he didn't want to ask anybody to call her for him, because he wanted to hold onto the belief that she would come on her own. so that she could apologize, too, and have a talk about their friendship.

by the end of the first day, he knew she wouldn't come, so he wrote a letter.

his friends and family didn't want to believe it, but he knew he was dying.

on the second day, he wrote another letter. haechan stayed with him throughout everything, despite having a crush y/n.

during this, y/n was going through an immense amount of guilt, hearing from haechan about mark's situation. her feelings swallowed her up, removing her ability to think properly.

soon, her brain imagined a different situation: one, that didn't involve her, at all.

on the third day, mark wrote his final letter. everybody could see that his time is near, but didn't want to admit it. mark accepted that y/n wouldn't come and writes down everything he wants to say, despite the pain racking his body every single moment of his last hours. he told haechan the story between y/n and him, hoping that haechan would look out for her and give her the letters.

quickly after, mark passed away.

haechan told y/n, but her mind couldn't accept that she—in her head—had hurt him, much less caused his death. she refused to acknowledge this, continuing to text mark during the days she found suitable. they slowly progressed to being sent only at night, when she can't sleep because of guilt. she lost all her friends, too busy checking and staring at her phone, begging for a message to come.

eventually, she went through all the stages of grief, and decided to finally go visit mark's grave. through this method, she finally got rid of the guilt that had been squeezing the life out of her.

mark, during his last moments, told haechan to only give y/n these letters when she's ready. he would know when.

haechan held onto these letters, being there for y/n even though her point of view doesn't reveal everything he did to keep her sane: checking up on her, forcing her to keep up with hygiene, buying groceries and restocking the fridge, and just being a comforting presence.

the letters were the last things she needed before being able to truly live, again.

even though she lost her first love and the future they could've had together, she got her happy ending.

and you will, too.

i have one last message before you completely leave this story. (although, i hope a bit of my words stay with you.) read on to finally reach the end of this rollercoaster.