Owamiki

Canon
They only have interactions in the UDP

The two never interacted on-screen in canon. However, they share two events together in Danganronpa V3's bonus mode, Ultimate Talent Development Plan.

In one event, Mikan had been chasing after Mondo (because his hand was bleeding everywhere, which he didn't notice), only issue is that she keeps tripping and falling. She then begins to apologize repeatedly. Mondo yells at her to calm down, leading Mikan to start crying and pleading with him not to hit her. Mondo, of course, says he'd never do anything so pathetic and apologizes for shouting and promises he's not mad at her. When Mikan calms down and asks him to come to the infirmary so she can treat his injury, Mondo says getting his hands all scraped up from fights is no big deal to him, but he agrees anyway so Mikan won't cry anymore.

In the other event, Mikan checks up on Mondo to see if he injured himself again. Mondo is at first annoyed that Mikan views him as the type to injure himself often, but upon seeing her afraid of him, he assures her that he's not mad at her for thinking so and promises that he'll control his rage.

Fanon
Got it's fanbase due to UDP and the pairs "Nice girl, Bad boy" dynamic.