The Storybook Villain

Out on a mission, Class 1-A goes on a field trip to study crimes away from the city. During that field trip (that takes the course of a week), some of the young heroes go out playing a game with the others, when they go into a wooded area and encounter a villain based off of a Dungeon Master from D&D. The DM (Dungeon Master), opens his book he uses as a weapon, and the students, Izuku, Ochako, Katsuki, Shoto, Eijirou, and Iida get trapped inside. Inside what, though? Inside a fantasy story the Dungeon Master controls. Trapped with no way to get out, and a villain as a God, controlling where the story goes, it'll be a long journey for these students that they've never experienced before. (Rating Mature due to possible sex scenes, violence, and language (thanks Bakugou).)