Angry Mom (2015)

both are dramas about corrupted education system with main leads who would do anything to change that for the better.

no angry mom pretending to be a teen in Imitation, but both start the same way and their tragedy might be similar

Both dramas have a woman/girl that has t different age as the people in her class
Both dramas have a secret identity
Both dramas are comedy
And lastly both dramas the girls are really good fighters

Both are about high school students. Both are really good dramas, not really centered around romance. However, there are some cute realitionships in both of them. Angry mom is more darker in my opinion.

Both have a strong mother female lead that enters the workforce and protects their precious but bullied daughter. This is the main plot for Angry Mom however Perfume's main plot revolves around a love story.

Old Person go to High School both got same vibe and Both dramas have a secret identity. If you love Angry mom then you will love My Boss, My Hero Japanese Drama.

Different plots on the whole, but I feel like both sort of tell the story of a person that was backed into a corner and how she tries to fight her way out. Also, both dramas deal with both very evil characters and those with shades of gray. Both are on the darker side (AM is Def darkerr) with specks of humor. Finally, both have story that really sucks you in.

Both have strong female leads that tackle injustice that happened to someone close to them.
Angry Mom tackles injustice in school and Whisper tackles the injustice in the law and judicial system.

Angry Mom is about a mom disguising herself as a student to find out what happened to her daughter, while Class of Lies is about a lawyer going in as a substitute teacher?

The main similarity between both dramas is the main characters pretending to be someone they're not. In Angry Mom, a mom pretends to be a high-school student to protect her daughter. In High School King of Savvy is about a high-schooler pretending to be a successful CO.
Warning: Angry Mom is surprisingly a very serious story that doesn't shy away from bullying and child abuse. High School King of Savvy is a goofy comedy that is very weird but has a lot of charm with its characters... The atmosphere is very different but both stories do have a similar theme with the main characters.

They're not really alike but give me the same heartwarming feeling. Both are family dramas - though this one isn't as heavy as Angry Mom - with great acting and realistic problems with unrealistic behavior (which makes it funny).

This is very similar- except it is not the sister it is the mother who returns to her daughters school to find out the truth of an incident that occurred. This is a highschool drama and also contains similar themes eg sexual assault.

The main character in both dramas seeks to uncover the truth behind a suspected bullying case

Both female leads had their daughters when they were young. Also they both are fighting for justice. Kim tae hoon is also present in both of these dramas.

There's no angry mom in Gokusen but there is some organized crime involved but more like Han Gong Ju-style, there is a righteous teacher, a stupid vice principal and unruly students, but also some rather preachy dialogues/monologues. Regardless, both are a fun watch with darker themes (Angry Mom is upfront with it, if not a bit gory at times while Gokusen is more careful, mostly if you care to think hard and long enough since Gokusen's premise relies more on comedy) as the students mature and grow through their actions.