Shotaro Terauchi is the serious and reserved captain of the Ionodai High School skate-leading team. He possesses short green hair and brown eyes, typically dressing in a blue shirt with black shoes under his jacket and pants. Prioritizing the team's well-being, he approaches skating with dedicated focus and makes decisions aimed at benefiting the group's cohesion and performance. Though not overtly expressive, he demonstrates underlying concern for his teammates, earning him the informal title of the team's "dad" from Yukimitsu.

Before high school, he declined an invitation to join St Cavis Gakuen High School to remain with his peers at Ionodai. When Kensei Maeshima sought to join the team, Terauchi expressed reservations due to concerns about potential distractions, though less strongly than Itsuki Kiriyama, having recognized Kensei's lingering passion and skill after observing a prior performance. Terauchi later intervened to grant Kensei an opportunity following a training plan violation, proposing a decisive one-on-one skate-off to determine membership. Terauchi won this match, though its fairness was questioned due to his acknowledged advantage, leading to a three-person match for resolution. His acceptance of Hayato Sasugai and Kensei as full team members followed his team's victory in that event.

His surname Terauchi translates to "temple" (寺) and "inside" (内), while his given name Shotaro means "right, proper" (正), "thick, big" (太), and "son" (郎). Kensei occasionally refers to him informally as "Sho".