Danganronpa 2: Goodbye Despair Anniversary Edition

They look like stickers.

First Island: Chapter 1

The first one is in Hajime's room. Just look up to the ceiling to find it. It must be found before proceeding when playing for the first time.
The second one is in Rocketpunch Markets, next to the vending machine.
The third Monokuma is in the Airport sitting on the red piece of luggage in the baggage claim to the right.
The fourth Monokuma can be found in the Old Building's Office.
The fifth and final Monokuma will be found in the victim's cabin.

Second Island: Chapter 2

The first Monokuma is on the water of Chandler Beach, which is behind the Diner. It is floating in a little dingy.

The second Monokuma can be found on the top of the aisle in the Pharmacy, right where the cursor is.

The third Monokuma is in the Library where the cursor is as well.

The fourth Monokuma is inside the closet in the Beach House on Chandler Beach. It is only accessible after Deadly Life begins.

The fifth and final Monokuma is in the victims cabin

Third Island: Chapter 3

The first Monokuma can be found off to the right side in the Movie Theater's lobby.

Look over Kazuichi Soda's head while on Electric Ave to find the second Monokuma.

Go to the end of the hallway in the Hospital and turn right. The third Monokuma is directly across from the stairs.

Once you can go up the stairs in the Hospital, you will find the fourth Monokuma in the Conference Room.

You will find the fifth and final Monokuma in the second victim's motel room bathroom.

Fourth Island: Chapter 4

The first Monokuma is on the back of the roller coaster.

The second Monokuma is hiding on Nezumi Castle over Kazuichi's head.

Strawberry house 3rd floor, beside the Stairs is where the third Monokuma is found.

The fourth Monokuma is hidden in Monokuma Archive in Grape House, accessible after Free Time begins. The Monokuma is hard to spot, hidden closely behind the golden statue in front of the bookcase directly to the right of the entrance.

The fifth and final Monokuma is in the Standard Room in Strawberry House. The Standard Room can only be accessed after Free Time begins. (Cannot be seen when playing as Nagito Komaeda).

Final Island: Chapter 5

At the Vendor Stalls, you can acquire the first Monokuma to the right.

The second Monokuma is on top of a pile of Monokuma plushies at the Factory.

The third Monokuma is at the Military Base, to the left and above the trucks.

At Sea King Industries, you should see the Fourth Monokuma to the right.

In the victim's cabin, to the right. The fifth and final Monokuma is bathing in the bathroom.

Hope's Peak Academy: Chapter 6

In the starting area, look to the right and above for the first Monokuma.

In the Gym, look to the left to see the second Monokuma.

In the Bio Lab, look under the desk for the third Monokuma.

In the Office, to the right of Kazuichi is the fourth Monokuma.

In Classroom 2-B, you can grab the fifth and final Monokuma next to the vending machine on the right.