Ultimate Imposter met Ryota Mitarai prior to the events of Despair Arc, after the latter collapsed on the floor in a hallway. After doing research on him, Imposter suggested he'd take Ryota's identity so that the Ultimate Animator could focus on working on his anime. Imposter has been visiting Mitarai ever since, bringing him food and drinks.
After Ryota neglected his health again, Imposter brought Mikan Tsumiki to nurse him back to health. After doing that, Imposter shared their secret with her. The two have been visiting Ryota together ever since.
After being brainwashed by Junko Enoshima's Despair Video (an early version), Mikan attempted to have sex with Ryota while explaining the video to him.
In Hope Arc, both Imposter and Mikan, along with their other classmates and Hajime Hinata/Izuru Kamukura, told Ryota to join them in atoning for their sins on Jabberwock Island. The group forgave each other their past mistakes.
In the bonus mode of New Danganronpa V3, there is an event where Ultimate Imposter brings Hifumi Yamada to Mikan after the Ultimate Fanfic Creator was overworking on his doujins. Imposter comments that he had Mikan help his friend in a similar situation, meaning their friendships in the universe of this bonus mode are similar to the ones from Despair Arc, with the only exception being Imposter still being disguised as Byakuya Togami.
The friendship between the trio was one of the most well-received parts of Danganronpa 3: The End of Hope's Peak Academy.
- Ryota/Ultimate Imposter/Mikan tag on AO3
- Ryota Mitarai & Ultimate Imposter & Mikan Tsumiki tag on AO3
- Ultimate Imposter/Mitari/Tsumiki tag on FanFiction.Net
- Mimiki refers to the ship between Mikan and Ryota
- Mitworai refers to the ship just between Ryota and Ultimate Imposter
- Twomiki refers to the ship just between Mikan and Ultimate Imposter