Ko appears in Suikoden II.
During Dunan Unification War, when Tir McDohl was in Banner Village, Ko told Riou, and as a result, Riou wanted to meet Tir but Gremio didn't allow it, so Ko planned to act like he was caught by a bandit to distract Gremio. The plan worked successfully and Riou meets Tir, but it was later revealed that Ko was indeed kidnapped by real bandits. As Tir, Riou and Gremio went to the forest, they meet the bandits and reveals that Ko were left behind deeper in the forest, because of a monster. Riou and co. decided to keep going, and they find Ko. However, it's revealed that Ko has been poisoned, by a monster which is revealed to be the worm Riou fought before. Riou and Tir fought the worm, but when it seemed the worm was defeated, it's revealed that the worm was a Poison Moth. Riou and co. eventually defeated the moth. After the moth was defeated, Tir got the idea to bring Ko to Toran Republic's capital, Gregminster. Ko was treated by Doctor Liukan to full health, and was escorted back to Banner Village.