GTO

GTO, this time a former gang leader now turned teacher who looks to help his students.

It have similar story (ex-delinquent turned teacher) and the teacher help the students to become better. GTO is a bit darker than Gachi Baka!

It's a similar story, with a sort of shady guy coming in and befriending a class, and the star also has awesome facial expressions.

The main character and the episode type are similar. The main difference is that GTO is set in a school and IWGP is set in the street.

Both dramas take place at a school. Both dramas have a cool main character and both dramas focus more on real life social problems of school than romance.

Both dramas have teachers that are determined to change the lives of their students and defy a corrupt system.

same plot line, different characters.

The film shows Chan Ho Nam , Chicken Chiu and their friends being recruited by Uncle Bee and joining the "Hung Hing" triad.

The theme used in both of the drama is quite the same..

It's about school life.

Entertaining big families that come close to heart.
The way both dramas deal with family-only dynamics is peaceful.
Full of comedy.
Heart-filling romances.
Double in-law couples.

Very similar storyline of former-bike gang member becoming a teacher for a class of students that are notoriously difficult.

similar humour, both dramas have a teacher-like figure that does somenbizarre things to give people a lesson.

I would say GTO is much better quality. You can watch any GTO anime or series. Both are about right and wrong.. and daily life situations. even though settings and plot is different, main ides stay kind of the same in both dramas.

Both series are about teachers that come to make order in a school. Both are about helping troublesome children. Both are comedies.