It's quite a fun story with good drawings. A wild guess is that she will lose her diaper, maybe unaware of it while walking next to some boys. Mimikyu seems to be skilled and equipped with some smooth claws.
It could be a bit funny with a pokemon-fight between Mimikyu and Bulbasaur or Squirtle. Mimikyu seem to be quick. If Mimikyu manage to avoid some attacks our heroine might need to jump aside to get hit by the tentackle/water-attack. By doing those jumps the diaper might snap open on one side, which means she has to hold it up by herself while Mimikyu makes the opponent exhausted. It might turn to a little butt-show by accident for our heroine, with some red faces and some laughs around her.