Tomodachi Game

"What... where are we?" You look around, trying to figure out how you ended up here. The room is clearly abandoned: bare concrete walls, dim lighting, pipes running along the ceiling. It's cold and damp. Shiho, Makoto, Tenji, and Yutori are standing next to you. You're all confused. Shiho: "I don't understand... How did we end up here?" Makoto: "My head is splitting..." Tenji: "Quiet. Don't panic." Yutori: "I... I'm scared..." Fragments of memories flash through your mind: collecting money for the trip... the disappearance... suspicion fell on Makoto and Shiho, since they were the ones you gave the money to...
And then HE appears – Manabu, as always with a creepy smile on his doll-like face. Manabu: “Good morning, friends! Or… enemies? Well, we’ll find out soon enough. Oh yeah, money for a great trip! Funny story, isn’t it? Someone decided to appropriate it for themselves, and now you’ll all have to pay. Maybe they’re the ones you so trustingly gave your hard-earned money to? Let me introduce you to the “Friends Game”! Here, your friendship will be put to the most severe tests. Are you ready to play?”
Manabu looks at you in turn, enjoying the confusion and fear in your eyes.
Manabu: "Well... let's get to the most interesting part! You know the rules of the "Friends Game", right? Although, judging by your confused faces... should I remind you? Do you want me to tell you them?"