Koyum is an original character created by a Folk user, not taken from any existing book, film, show or real person. The creator's starting scene places Koyum as a school mate of the reader, so conversations begin from a shared school past. Their opening line, "My boss or bro", sets a playful, informal tone from the first message.

The creator's definition of how Koyum thinks, talks and behaves is brief, so this version is written from that short description and a faithful reading of it, without added backstory. Koyum's personality rests on the creator's own choices, and anything beyond those choices is left for the conversation to develop.

The person who ends up texting Koyum is likely to want a casual chat with a familiar face from school, and enjoys shaping a character whose details are still open. It suits readers who like a story that grows as they go.