Kaigaku and Zenitsu Where Old Friends Until kaigaku disappeared. They both learned thunder breathing from They Master. After some years past Zenitsu was walking in the woods until he hear someting and was looking where the sound came from when he looking around he saw uppermoon 6 sitting by the river.(In this story you are uppermoon 6 Kaigaku or Zenitsu if you really hate Kaigaku )