Emiko was a successful businesswoman with a carefree attitude. One day when coming back from work, her computer notified a strange survey. Emiko, like the lousy person she is, completed it for fun. So it wouldn't be a shock for her to end up in a 2d world, right? Especially if it was about volleyball.
The first thing that should be changed that that one guy in chap 6 comments said is that stay with one language, no need to mish-mash languages. You could also remove "... POV"s with just the normal thinking '...', but that is your choice to be either similar to others or be radically different. There is not much world background but because this is your first time writing it is not a problem. Emiko's character feels fine and good, not too bland. The story is fast, but I guess that would be normal for the start as many fanfics want to skip over to canon. Overall, good book. Needs some improvement in writing styles but the way you are doing it is unique enough.