This is a student guidance teacher at the senior high school Fuutarou Uesugi is attending.
He is a tall middle-aged man with a very muscular physique.
Second Year Midterm Exam Arc
Fuutarou and the five quintuplets woke up late on the day of the mid-term exam. The group rushed to the school and only Yotsuba made it in time, while the others became occupied with unpredictable circumstances on the way. The student guidance teacher was guarding the school gate. By disguising as Yotsuba, the remaining quintuplets, Miku, Ichika, Nino and Itsuki, made it past the school gate with the teacher barely noticing. Fuutarou tried the same trick but was caught by the teacher, who then dragged Fuutarou to the teachers' office as punishment for being late.
School Field Trip Arc
After Ichika and Fuutarou were caught in the warehouse, the teacher gave Fuutarou a long, severe scolding.