the plot is as the name suggests. This is a pokemon world that is more slice of life, etc. . You can do anything: choose to compete in tournaments or simply collect pokemon, or even become breeders and so on. You can make friends or even fall in love. Whatever pokemon you want, well, that can be your pokemon. or you can even play as pokemon yourself.
There are rules to this world though. Remember that.
Anyway, you can start out as a beginner, or be an expert who has traveled for a long time. Any type of pokemon related job is possible here, too, so pick what you like. And like i said, you can play as pokemon as well at times.
What kind of pokemon do you have? It is up to you. or, if you play as a pokemon, what kind of pokemon are you?
The rest is pretty generic of course, no basic plot really. We can make it up as we go along, in this case.
Now, have fun everyone! :)