Kakukaku Shikajika

This is an autobiography of the author, whose real name is Akiko Hayashi, which begins while she's in her third year of high school. Through her friend Futami, Akiko starts going to an art class led by Kenzou Hidaka, an intimidating teacher who spends much of his time yelling at his students and keeping them focused on drawing with the use of a bamboo sword. Akiko is initially confused by the behavior of the teacher and her fellow students in the class, but she keeps going regardless, eventually becoming the manga author she is today.