Although the two never interacted in the game due to Mukuro being disguised as Junko Enoshima, as well for her early death in game. The two share some similarities, they're both known to be fighters as Mondo shows a delinquent type of persona, meanwhile Mukuro is the Ultimate Soldier. It's unknown if the two interacted during the duration of two years of memory loss, but their desks were right next to each other. The two also sit next together in the dining table and are the only ones in the game who've used violence against Monokuma except Mondo doesn't get killed for breaking the rules and Mukuro does.
In Danganronpa: The Animation afterwards of Sayaka Maizono's murder, Mukuro is killed by Monokuma (who Junko operates) and Mondo is shown in distraught as she's stabbed by spears due to not following school regulations as she assaulted the headmaster. Mondo is shown placing his long overcoat over Mukuro's dead body afterwards, showing his respect towards her even being dead.
During Chapter 5 in Danganronpa: Trigger Happy Havoc IF storyline, Mukuro is saved by Mondo on a motorcycle Junko used for Mondo's execution in game. Junko is described to trying to injured her sister with the motorcycle but luckily Mondo was on the motorcycle. Junko tries to make Mondo turn against Mukuro but he refuses he states he can't let a girl get hurt, afterwards Mondo pulls Mukuro on the motorcycle in order to flee from the stampede of Monokumas.
They don't share a lot of similarities but what they have on common is that both have a family (with Mondo having his brother Daiya Owada and Mukuro having her young twin sister Junko Enoshima) that they killed or the family itself had killed them; with Mondo thinking that he killed his brother and in Mukuro's case her own young twin sister killed her while controlling Monokuma as result of Mukuro breaking the school rules. Furthermore, the person itself had died later with Mondo being executed for killing Chihiro Fujisaki and Junko dying by her own execution after being found out as the mastermind by Makoto Naegi along with his other companions.
The ship isn't very popular due to having much more popular rivals like Ishimondo and Naekusaba. Although the ship has a very small amount of supporters the amount of fan fictions on AO3 is very minimum and only has around eight stories at this time.
- Class 78th refers to the ship between the two and the other students of Class 78th.