He didn't talk in the beginning but now, he is an enthusiastic and professional mangaka.
Detective Trap's Serialization
He did the figures, both sketches and inks. Miuro says he is the best artist of the new assistants he's in charge of. When he first starting working for Trap he didn't talk. Takahama opens up to Mashiro when Kato and Ogawa leave the studio. When Mashiro and he are the only ones left, and Takahama finally talks to Mashiro. He says that he wants to work for Disney and since Mashiro is serialized while he is still in high school, he feels that Mashiro is equally as ambitious, and so he feels like they would have a lot in common. Takahama didn't talk while Ogawa and Kato were there because they're happy with being assistants. Ogawa, he can tolerate, because he tries to sharpen his skills, while Kato doesn't. When Mashiro and Takahama are the only only ones at the studio, they usually talk about manga. Eventually Takagi joins in their discussions too.
Business Boy Kenichi's Serialization
Takahama gets his own series, Business Boy Kenichi, and his assistants were Takuro Nakai and Kato. However, the series gets cancelled later. Takahama returns to be an assistant for Run, Daihatsu Tanto! when it is being published.