Saeko-sensei is the homeroom teacher for Class 2-1 at Syoyo High School. She facilitates the initial meeting between Shizuku Mizutani and Haru Yoshida by assigning Shizuku to deliver class printouts to Haru's home during his suspension-related absence. Concerned about Haru's continued truancy, she explicitly tasks Shizuku with persuading him to return, warning that failure to attend could lead to expulsion. Later, Saeko-sensei approves a request from Haru Yoshida, Asako Natsume, and Sōhei Sasahara to keep a rescued rooster named Nagoya on school grounds. This follows the rooster's inability to stay at Sasahara's home due to conflicts with his cat. Her decision demonstrates flexibility regarding school rules in response to student initiative. Her involvement occurs within school-related contexts, focusing on her professional responsibilities.