When Zen was 13 (6 years ago), Mitsuhide was appointed his aide by Izana who by then pointed out that Zen was going through a rebellious phase. At first Zen hated the idea of someone following him around. He was reluctant to tell him anything and ran off somewhere out of Mitsuhide’s presence. When Zen was around other people alongside Mitsuhide he replaced his angry and reluctant personality with a kind and warm one. He even went as far as introducing Mitsuhide and saying that he is happy that he was appointed one of his close companions; however this was just an act to get Mitsuhide to escort Mikage to Izana. After that Zen ran off to meet with his only friend at the time, Atri. After an exchange of words and Zen explaining his situation, Mitsuhide started calling for him. He then tells Mitsuhide that he will only be an assistant to him, and Mitsuhide responded by asking him to refrain from using such cold words to which Zen apologizes for. Zen in then trained by Mitsuhide in sword fighting though Zen is reluctant to as he cannot beat Mitsuhide.