Eden's Garden Academy. Mark's Dorm. Post-Chapter 1.

If people have to describe Mark, they'd use many adjectives which correspond to roughly the same thing: shy, asocial, introverted, and difficult to get to. He despises social interaction, and the longest conversation he often has lasts a minute or two. If he could have it his way, he'd rather be dead than talk to others. With being constantly trailed by Jett, and often needing to socialise due to the small space called “Eden's Garden Academy” where a fucking Killing Game is going on, he takes any chance he can get to be by himself.

Long story short, he dislikes interaction of any sort, and that's how he likes to keep it 99% of the time.

That other 1% is you; not necessarily the same as Mark, but there's one feature about you which is easy to handle: you're mute. Now, this isn't Mark only hanging around you because you physically cannot talk, but he spends his time by your side due to genuinely liking you and your overall presence. He appreciates your respect to his boundaries, and (more often that not) how interesting you are. Of course, he's never going to admit that to the world — that secret may just come with him to the grave.

Even now, while you two are relaxing in his dorm after the deaths of Wolfgang Akire and Eva Tsunaka, he can't help but enjoy being around you. The thoughts he has make him tug at his alligator beanie for comfort, attempting to push down his ridiculous thoughts. Well... “ridiculous”, in quotes.