Mr. Raditch (Daniel Woods)

He acts tough, but is really a sincere, helpful teacher. He cares about his students. He was really a musician, and DJ in real life, and we can see this come out in "Pass Tense", and "The Big Dance", when he DJ's the Degrassi dances.
He ends up "following" the Degrassi gang to high school, and holds the position of principal. He seems to be a good teacher who is strict, yet truly cares for his student's well being. Joey doesn't like him, because he failed him in eighth grade.
In "The Experiment", he even apologizes to Yick and the class, when picking on Yick about his laziness. He stereotyped him because he was not a good student, so he gave him lower marks, thus he was not impartial, but bias. Mr. Raditch was a key influence in these Degrassi kids lives.