Seo is tall with blue hair and blue eyes.
Seo has a friendly attitude and acts kindly to Hinohara. Seo does not take things too seriously and isn't one to become frightened easily.
He listens to Arata's problem and his quest to save the Princess, Kikuri and questions why he took such a job, and guides him towards Kotoha, by telling him to take full awareness of his surroundings and then disappears when Arata looks back.
- When translated from kanji, Seo (先生) means Sensei.
- Since the kanji for Seo means sensei, Seo name is most likely an alias and that his true name is "Amahi", point out by Saruta.