I watched Glory and read the bullied manga and holy shit there's a lot of parallel's I can draw from this.
Moon Dong-Eun and Yuichi Aizawa share a very similar history with critical differences.
Similarites
-Both bullied by a high status group of students, brutally even (both have visible physical scars that stay with them permanently). They both had to drop out of school because of this.
-Both tried to get help, but they didn't help them
-Both spent years plotting revenge against their former bullies
-Both are calculated and cold individuals, you can't tell if they're good or not
-Both are methodolical
-Both utilized the ringleaders cronies to exact their revenge, weather through aligned goals or blackmail
-Both destroy their bullies lives by taking everything away from the, leaving them completely alone, creating the same hell they were once in.
-Both became teachers for the purposes of their plot. They also use that position to get close to the ringleader's daughter.
Differences
-Dong-Eun was not just alone. The people closest to her didn't give a damn about her. Not much is known about Aizawa's family
-Dong-Eun at least had a friend in Kyung Ran before it ended (though she had the school nurse to console her), whereas Aizawa had no friends
-Dong-Eun's homeroom teacher knew the bullying was going on and turned a blind eye, even abusing Dong-Eun himself. Aizawa's homeroom teacher was negligent at worse.
-Dong-Eun comes across as cold and distant, view it necessary to keep her hatred alive. Aizawa was similarly cold, but showed more warmth to Shiori
-Dong-Eun's main journey is getting her revenge on her bullies. Aizawa only focused on his revenge near the end of his story as he mostly kept an eye on Shiori
-Dong-Eun's bullying was arguably more brutal than Aizawa's, which is hard for me to say since they tried hitting aizawa's face with a baseball.
-Dong-Eun's master plan was on systemic destruction of their lifestyles, while Aizawa focused more on gathering evidence and posting personal information online.
-Dong-Eun recruited allies to help her in her revenge, whereas Aizawa went solo
-Dong-Eun is very transparent about getting her revenge right to her bullies face, whereas Aizawa lies about not holding a grudge against his bullies
-Dong-Eun eventually has her own romance with Yojeong, whereas Aizawa never got involved romantically
-Both were willing to do illegal things, however, the nature of it differs. Dong-Eun considers framing people for murder by planting evidence, while Aizawa tampered with technology to install both a monitoring gps and spyware so he can see online activity.
Then there's the bullies, Yeon-Jin Park and Shinji Suzuki
Similarities:
-Both left physical scars on their victims
-Their cronies send fake apologies to their main victims
-Both had flimsy reasons for bullying their victims
-Both come from influential backgrounds (Yeon-Jin comes from wealth, Shinji was a popular class president)
-There's romance within their friend group (Yeon-Jin and Jae-Jun, Satake and Takano)
-Both feel no remorse for their bullying behaviour
-Both work highly respectable jobs and have the perfect family
-Both cheated on their spouses
-Both love their daughters
-In the end, both end up alone and isolated
Differences:
-Yeon-Jin was more sadistic, breaking into Dong-Eun's house and burning her with the curling iron. Shinji has not shown to break into Aizawa's house (but he burned his body with cigarette scars), and he tricked Aizawa into believing he wan gonna pour acid on his face.
-She bullied multiple girls, whereas Shinji only had his eyes on Aizawa.
-Shinji really love his daughter, whereas Yeon-Jin sees her daughter as somewhat an extension of herself
-Yeon-Jin bullies people out of boredom, whereas Shinji made Aizawa's life a living hell over getting a better score than him, preventing him from getting a video game.
-Yeon-Jin's cheating only served to benefit Dong-Eun's plan, whereas Shinji's affair with Yazaki is what started Shiori's bullying and nearly drove his wife to suicide.
-Yeon-Jin does show affection to her husband and doesn't abuse him, whereas Shinji abuses his wife and apologizes afterwords for repeating that pattern
-Their endgames are different. In the Glory, Yeon-Jin and Sa-Ra are in prison (Yeon-Jin now being a bullying victim of inmates), Jae-Jun and Myeon-O are dead, and Hye-Jeong loses her voice. In IIMFIGB, Satake and Takano are still alive but have their reputations ruined, whereas Shinji gets a taste of his own medicine before being killed by one of his present victims.
Now we get to the daughters, Ha Ye-Sol and Suzuki Shiori
Similarities
-Both are daughters of the ringleader, whom love them very much
-Both have their parents bullying victim as their homeroom teacher
-Both are incredibly kind, sweet, and empathetic
-Both disowned their parents after learning of their bullying history, choosing to spend the rest of their lives with the other parent instead.
Differences
-Ye-Sol was just in elementary school and lived a normal life. Shiori got subjected to bullying in middle school
-Ye-Sol is a product of an affair between Yeon-Jin and Jae-jun, passing her off as Do Yeongs child. Shiori is the direct biological daughter of Shiho and Shinji Suzuki
-Ye-Sol is color blind, whereas Shiori has perfect vision
-Ye-Sol hasn't developed much to be conscious of outside things, whereas due to her bullying, Shiori is watchful of her surroundings
-Ye-Sol's friend is afraid if she's gonna start bullying her, whereas Shiori's friend, Yumi, eventually joined them.
-Ye-Sol immediately disowned her mother after seeing her bullying past publicly exposed, whereas Shiori was coming to terms of who her father really is before finally disowning him.
-Ye-Sol was never really that close to Dong-Eun, only seeing her as her mom's "friend", whereas Shiori was initially skeptical of Aizawa, grew to trust him and have more of a close bond with him to the point discovering her dad bullied him led her to disowning her dad.
Then there's the bully's spouses, Ha Doyeong and Suzuki Shiho.
Similarities
-Both are married to bully characters without knowing their history
-Both have spoken with their spouses victims
-Both were unsettled when they dig deeper about their spouses
-Both got cheated on by their spouse and then eventually divorced them at the end of the series
-Both vowed to take better care of their children after their spouses horrific actions have gone public (this also highlights Do Yeongs character considering he found out the truth about his daughter)
Differences:
-Do Yeong was in a transactional relationship with Yeon Jin from the start, only valuing her for her looks and being a trophy wife. Shiho believed she had a loving relationship with Shinji and did everything she could to make herself and her daughter the perfect wife/mother and daughter (though Shinji believed she baby trapped him)
-Do Yeong is a CEO of his company, whereas Shiho is a house wife.
-Do Yeong was very attentive to his daughter Ye-Sol, whereas Shiho was critical of Shiori despite being a loving mother
-Do Yeong had more personal interactions with Dong-Eun, while Shiho spoke to Aizawa where it was socially expected for a homeroom teacher.
-Shiho is a kind soul who stood her ground against Shinji, while Do Yeong took drastic measures to take care of Jae Jun so he doesn't come near Ye-Sol
Then there's another parallel, but just 2 similarities. Son myeong-o and Choi Hye-Jeong are resentful lackeys of yeon-jin, sa-ra, and jae-jun, betraying them for their own benefit. Takano and Satake also resented Shinji for his success and worked to bring him down.
Eri Yazaki wants Shinji to leave his wife so she could marry him and become Shioris stepmom, whereas Jae-Jun wants Yeon-Jin to divorce Do-Yeong so he could be with her and take his position as Ye-Sol's biological father. Also Jae-Jun is an unrepentant bully, unlike Yazaki, who is firmly against bullying