Himitsu no Hanazono-sensei

The main character, Hikari, is a cheerful girl who is far from popular. However, her desire to fall in love was overwhelming, and she confessed her love to three people within a month of entering high school, which earned her the nickname “Runaway Batting Machine.” Then she meets Hanazono, a serious teacher who is strict about violating school rules. Mr. Hanazono brings a ray of light to Hikari’s love life, which has been full of failures.