During the events of Undefined Fantastic Object, Ichirin and Unzan were acting as guards for Byakuren's ship, to keep out anyone trying to keep her from being revived. She initially thought the heroines were attempting to stop her, but upon realizing they had some parts of the treasure needed to unseal Byakuren, she assumed they were on her side and happily let them through.
Unzan is a pink/reddish cloud with the face of an old man with a beard.
A shy, but overbearing nyuudou, Unzan is quiet and stubborn, with a strong sense of duty. While once feared, together with Ichirin, they rarely attack anyone.
- Ichirin Kumoi (Controller)
- Unzan is the Stage 3 boss in Undefined Fantastic Object; Ichirin herself came as a way to have an actual character on the screen to shoot at.
- Unzan is the first male character to appear in a Windows game.
- The characters for Unzan's name mean "Clouded Mountain" or "Mountain of Clouds".
- A nyuudou cloud (入道雲) is a Japanese term for cumulonimbus cloud or thunderhead.
- Unzan being purple is a reference to the purple cloud leading to where Myouren was.
- In an interview with ZUN, he states that Ichirin isn't the only one that can hear Unzan. Rather, he's just shy and tends to whisper, so Ichirin repeats what he said to others "Like a spokesperson".