Ryuuzen Gotou

is a teacher at Yamaboshi High School. He also acts as advisor to both the Jazz Band club as well as the Student Cultural Society club, which the main characters are a part of. In addition, he is the homeroom teacher of Class 1-3, which includes Taichi, Iori and Inaba. Gotou comes off as a bit lazy and goofy but he can be quite insightful when he wants to be. He likes his students to feel at ease around him, so he allows them to refer to him by his nickname, "Mr. Go".

When Heartseed wishes to communicate with StuCS members, he most often takes control of Gotou's body to do so. The reason for this is that Heartseed claims Gotou is one of the few people who won't at all question why they blanked out after being possessed.

Personality
Gotou can easily be described as laid back and friendly. He rarely takes things seriously and even overlooks his students skipping class. He is depicted as rather lazy and the main characters state he almost never gets involved with their club, a trait they also enjoy. Despite this, Gotou has on occasion shown capable of giving excellent advice to his students, which even surprises him.

Appearance
Gotou is a man of average height and slim build. He has short, unkept black hair and typically dresses in simple button shirts with a tie. He has hints of facial hair along his lips and chin and dark black eyes.

When possessed by Heartseed, his eyes become droopy and his pupils lose their gleam.

Friends

 * Taichi Yaegashi: One of Gotou's students in his 1-3 Class. Because Gotou is the advisor of the StuCS, he often interacts with Taichi and during the Kizu Random arc, Gotou reminds Taichi what it means to be a friend and helps him overcome his doubts.
 * Fujishima Maiko: Because Fujishima is his class' representative and Gotou is, himself, lazy, he often defers responsibilities to Fujishima, such as planning the class trip.

Trivia

 * He is skilled at playing the saxophone
 * Apparently, Gotou always chokes when he eats hot food.