Makihara Rieko

The chemistry teacher and the school nurse, as well as the homeroom teacher. She also advises the student council.
She is a suspicious person who seems to have an ulterior motive, and is unable to be read.
Her hobby is to tease the students with her overflowing sexuality, and the MC is often seduced.
Her deadpan often makes other wonder if she's serious or joking about things.
She is greatly amused by the current situation going on, and is teasing the MC and the girls involved.