Based on a shoujo manga "Seito Shokun!" by Shouji Youko, serialized in Kodansha's Shoujo Friend.

Students who do not trust teachers, teachers who give up faith in education, parents who blame schools for their children's misbehavior...

Naoko was at a loss when she was assigned as a new high school teacher. Times have changed and students are no longer easy to control, but she chose not to look away. Instead, Naoko reaches out to try and discover the various issues hidden in the modern education system.

(Source: AniDB)

Watch Seito Shokun! Kokoro ni Midori no Neckerchief wo Online