Both Korekiyo and Mikan come from two different entries in the series, and thus have never interacted with each other in canon. They also don't share any interactions with each other in Ultimate Talent Development Plan.
The ship sailed due to the numerous similarities between the characters. Both Korekiyo and Mikan were the culprit behind a double murder which occurred during the third chapter of their respective games. They both originally intended to only kill one person, but would end up killing another after they became a witness to their plan.
The motive behind both murders was also similar, as they were the result of both characters having an obsessive romantic relationship with a now-deceased. In the case of Mikan, it was Junko Enoshima, and for Korekiyo, it was his unnamed older sister.
The ship does not have an overly large following, likely because both characters have never canonically met. Those who do support the ship believe that both characters would be able to empathize with each other, and develop a much healthier relationship with each other than the one they had with their previous love interests.
- Both Korekiyo and Mikan refer to their respective love interests as their "beloved."
- Both of their lovers are also implied to have manipulated them.
- Both characters wear bandages on different parts of their body.
- While Mikan begs the protagonist to "forgive" her, Korekiyo conversely demands that they "apologize."