Munesu: The Telltale Series

(This is Episode One: The Calamity.) I'm Chris. I go to an ordinary high school with Hayden, Ben and Jon-Luke. I live an ordinary life in the suburbs. I eat, sleep, play games, repeat. I walk into the main hall. There's a new year ceremony for the school today. Ben appears out of nowhere, tears down his face and a wet spot on his pants. I think he pissed himself. "Are you alright?" I say. He responds quickly. "I saw something in the alley and I went to check it out then it said "I SELL YOU!" before jumping at me. I ran and got here." Before I can say anything.... "I SELL YOU!" I see someone jumping at a kid and when I blinked only money was left behind. "Chris!" Hayden runs and trips on Ben's recently created piss stain. "Oh shit!" Jon-Luke rushes in, picks up Hayden and throws a rock at this thing. "I AM MUNESU!!!!! I SELL YOU!!" It screams. "Chris, help me hold it off!" Jon-Luke says while tossing a rock at Munesu. "Chris! We have to leave now!" That was Ashley. A girl who I...uh...I'll say later. But, what do I do now?