22 years old and a 4th year student at the start of the series, Mayama is from Kanazawa, Ishikawa-ken and an architecture student at the art institute. He lives in the same complex as Takemoto and Morita. He occupies room 101, sharing the floor with an unknown individual and formerly Lohmeyer-senpai. He acts as a senior to Takemoto and tries to help Morita get up for early morning classes. At one point, Takemoto and Morita are seen sleeping alongside him in his futon. Morita also borrows Mayama's shirts from time to time because it's more comfortable. Mayama also used to help Rika out with various errands while Rika was disabled due to the accident that left her husband dead. It is during that time that Mayama develops feelings for Rika. It is unknown whether Rika fully reciprocates the feelings that Mayama has for her, but various flashbacks imply that Mayama and Rika have 'fooled around', or Mayama took advantage of Rika's disability to fulfill his desires, although this is cleared up later as not being the case. Rika suggested that Mayama find another job so that she wouldn't have to continue hurting him, as she realizes how much he cares for her, and is unable (and perhaps unwilling at that point) to allow him to enter into her life. Mayama eventually landed a job at Fujiwara Design. He has to deal with coworkers that are also very interested in his love life, and make comments whenever they can. Mayama also has to keep watch of his boss, Nomiya, whom he considers to be a playboy, when Nomiya begins to take an interest in Yamada. Mayama doesn't return the feelings that Yamada has for him, but he sees Yamada as his close friend. Yamada's innocence is one thing that Mayama has to constantly guard from Nomiya, who has developed an interest with her. When Fujiwara Design later broke up, people had to either stay in the Tokyo branch or transfer to the Tottori branch. Nomiya arranged for Mayama to be transfer to the Tottori branch, but as soon as this was announced Mayama quit. He now works again with Rika at her company, Harada Design, after forcing himself into the position in his own way. Mayama's character design is based upon Suga Shikao.
Mayama is tall and has an average but rather muscular build, as seen when he was in the onsen, he has wavy orange hair and dark grey eyes. He has a mature look on par with is personality
He's mostly seen in light brown slacks and white long sleeves dress shirt along with black shoes. He's also often wears a light brown trench coat when the weather gets cold.