Isekai List #1

Sort of falls into this one since the souls of the two were swapped; spoiler alert as the MC will eventually learn she swapped places with her twin sister [eventually switches back too]

Pulled into a world that is about a novel within a game; two possessors pulled in. One from reading the novel, MC is from playing the game about the novel the one was pulled in. Trying to find the true ending of the world.