Teppei hails from Chiba Prefecture and appears as a supporting character in the anime's second season. His background as a Chiba native places him within the series' focus on regional cultural dynamics, often contrasting with characters from areas like Nagoya.

During Season 2, he becomes part of the main cast's social group, regularly appearing alongside characters such as Monaka Yatogame, Kaito Jin, and photography club members. His outsider perspective on Nagoya customs fuels comedic and cultural exchanges.

In Season 3, he participates in storylines emphasizing regional rivalries and personal challenges. Ahead of midterm exams in Episode 2, he faces academic stress, leading Jandara Rin, a Mikawa native, to give him a traditional Mikawa good-luck charm, demonstrating cultural specificity and their evolving dynamic. Later, in Episode 5, he explicitly declares a regional-based "war" against Jandara-senpai, reinforcing his Chiba identity and underscoring the theme of regional distinctions.

His development involves recurring collaborations and conflicts with other regionally defined characters, participating in group activities and serving as a foil to emphasize regional traits. His development remains centered on these cultural juxtapositions and lighthearted interactions without further evolution or backstory expansion in subsequent seasons or other media.