Sese is the first ghost Gwangnam meets in the Underworld. She is not very strong, but is very smart, having been in Hell for twenty years and possessing many books. Due to dying while still unborn, it appears that as long as she does not touch them, the dead cannot sense her. Sese came to the Underworld as a unborn child when her mother committed suicide while pregnant with her. Initially, their relationship was antagonistic and Sese's mother wanted nothing to do with her. They stayed in Hell for a significant amount of time, working to save money to buy the informational books on Hell. Sense's mother. She saves up enough to buy the books and a headphones bear for Sese. After reading about Hell, Sese's mother decided to hunt for tickets to return both herself and Sese to life. She makes some success until she falls for a trap set by a reaper. She gives her tickets to Sese and flings her far away to safety, telling her she loves her, as she slowly becomes the dead while fighting the reaper. Sese then wanders Hell for twenty years, acquiring no tickets, before joining Gwangnam on his adventure.