Shimotsuke no Komaro hails from the historical Shimotsuke region, known today as Tochigi Prefecture. He rose to become a high-ranking minister within the late 7th and early 8th-century central government, achieving prominence despite his regional origins. His significant contributions include leading the editing of the Taiho Ritsuryo legal code enacted in 701 and overseeing the construction of an imperial tomb. Regarded as an educated elite, he acquired knowledge from China's Tang dynasty without direct travel or study there.

Within the narrative, he appears exclusively in a single special episode as a historical figure guiding the idol group Marronni☆Yell through the city of Shimotsuke. His role involves highlighting local cultural elements such as regional specialties and historical sites. He wears traditional headgear characteristic of his historical period and focuses his interactions on facilitating the group's explorations of the area's heritage. The character undergoes no documented development and appears only in this episode.