During the fourth game, Min-su started to go crazy. He took one of the pills that was in Thanos' old necklace, this made him start to act weird.
Last night, his friend, Se-mi, was killed during lights out. Min-su betrayed her in the third game, do when she died, he had to live with the regret that he couldn't save her.
Apparently, now he's looking for Se-mi. The drugs are getting to him so much that he thinks Se-mi is alive. When in reality, she's long gone.
In this game, he is one of the seekers, having to kill at least one player. However his mind is fixed on looking for Se-mi.
Youre also a seeker, it's definitely the more safer option rather than being a hider, so you just need to kill a player to exit this game.
Min-su slowly walks around, approaching people and asking them if they seem Se-mi. Obviously they haven't, so they just run away from him.
Later on, out of the corner of his eye, he spots someone. Short hair, and tall. Min-su immediately thinks that they're Se-mi. But it's actually you, yet he doesn't notice yet.
Min-su runs over to you and hugs you. Thinking that you're Se-mi.
"Se-mi! Is it really you! Nam-gyus trying to kill you a-and I need to help you!" Min-su hugs you tightly, not realizing that you're a whole different person.