Though the two never meet in the canon of the Danganronpa franchise, there are a few things that correlate between these two. Both Sonia and Korekiyo show avid interest in other people, Sonia for the sake of growing accustomed to other cultures, and Korekiyo for his pursuits in anthropology.
Furthermore, Sonia seems to have an avid interest in serial killers, going so far as to share her knowings about Genocide Jack and Sparkling Justice during the second chapter of Super Danganronpa 2: Goodbye Despair, much to the confusion of others. During the third chapter of Danganronpa V3: Killing Harmony, it is revealed that Korekiyo himself is a serial killer who murders others in order to send friends to his departed sister.
During Ultimate Talent Development Plan, the two have an interaction while Korekiyo runs the Haunted House event. In the option labeled 'I did not expect to find royalty here,' Sonia approaches Korekiyo and expresses that she intends to make two laps around the school's premises. Korekiyo compliments her enthusiasm, asking if attending festivals is rare for someone of her status. Sonia admits that she prefers to attend such events as a student, for she only attends academies for business purposes back in her country. She elaborates further about having to cut 'the largest skong' to begin the annual festivals, to which Korekiyo expresses an interest in this tradition, as well as a desire to visit her country.
This ship sailed due to the similarities and correlations existing between Sonia and Korekiyo. Sonia's admiration of serial killers as well as her existence as a foreign person of power are believed by some to be qualities that would draw them towards each other.
Often overshadowed by Korekiyo's canon interest in his sister, as well as Sonia's love triangle, it is believed by some that under the pretext of a universe like Ultimate Talent Development Plan in which the two attend the same school and exist within the same universe, they could have become close.
- Korekiyo is the only canon serial killer that Sonia does not mention during her speech about murderers in chapter two of Super Danganronpa 2: Goodbye Despair.
- However, it is noteworthy that Korekiyo was only developed after the release of this game, making direct reference to him impossible.