Monisa

Monisa is a het ship between Monaca and Nagisa Shingetsu in the Danganronpa fandom.

Canon
Nagisa's character profile lists Monaca as one of the things he likes the most. In his memoir, Nagisa mentions Monaca is much more important than his own life. They're also holding hands on of Jataro's art works, meaning he ships the two.

Nagisa was impressed by how Monaca didn't give in to despair after Junko Enoshima's death. He developed a crush on her. This was shown when he was embarrased to answer Monaca's question whether he likes her, when Kotoko asked him if he's jealous of her friendship with Monaca, and when he told Komaru Naegi and Toko Fukawa that he will not let them hurt "their princess" Monaca.

Monaca eventually reveals her true nature to Nagisa in Chapter 4. She reveals she was never interested in a paradise for children and had no expectations for Nagisa. She then steals Nagisa's first kiss after he slaps her when she was getting close to him. Later, she kisses him once more and tells him she loves how worthless he is. Nagisa is seen broken afterwards, even during his boss battle with Komaru.

In Future Arc, Nagisa tells Komaru not to hurt Monaca because she still used to be their friend.

Fanon
This ship isn't popular because of the way Monaca abused and manipulated Nagisa.