Prinny: Can I Really Be the Hero?/High Tome Forest

Boss
Depending on when the Prinnies come to the Forest, they will face either Anise or the duo Kim and Chi. Just dealing with two bosses at once can increase the difficulty, so it's generally preferred to face Anise.

Kim and Chi
Kim and Chi are more difficult because there are two of them than because of anything they do in particular. The Prinnies will find it easier to deal with them if the pair are kept apart. Just stay away from them when possible and try to get a Hip-Bump on one of them when the individual attempts an attack. Both Kim and Chi telegraph their attacks by yelling and giving off a bright burst of light. They also conveniently stay very still while attacking, leaving them wide open to the Hip-Bump if the Prinny can avoid being hit in the first place.

Don't bother trying to stun both of them at once unless they're staying close together (try not to let them do that). As with most boss battles, stun one with a Hip-Bump and use a barrage of air-slashes to do some damage. Keep an eye out for the second boss, in order to avoid an attack if necessary. Two or three rounds of air-slashes on each boss and the battle will be over. Once one of them is out of the way the other will be much easier to handle.