Recommendations

The similarities is the work place, the relationship at work, funny friends but also dark past. I can't really compare it that much since Bed Friend is R-rated but a lot of things were actually similar there. The top best friend Jack/Jade. Terrible step dad and ignoring mother. Trauma. Homophobic people. Well, what is common between Uea and Cher is that they have undying love for their siblings. Cher and Thoop are not related by blood but treat each other like siblings too. Uea was able to go back to his hell for his loving sister that was the only green from his family. Cher was taking care of Thoop as well and even appeared in dangerous situations for him. In Bed friend it's Uea who's sexually assaulted, in ABAB it's Tian, Cher's past crush but her and Uea went through similar hell. Both were sexually assaulted by their step fathers. I'm not sure if Uea was also raped but I wouldn't be surprised. The difference is Uea didn't kill himself even after living in this hell for several year but still fought with PTSD. Tian ended up pregnant and couldn't live with herself anymore.
King and Gun actually shares more things. Both when they find the right one, they love him undyingly. Both were financially supporting their boyfriends and protected them in front of danger. How King beat Uea's ex and Gun hit Thoop's step dad. Both are visually outstanding and their boyfriends have them wrapped around their finger. They both come from problematic families who didn't accept their relationship at first but allowed it in the end. Both are pretty rich but fall in love with the poor guy with golden heart. And Cher and Uea are both sassy to their boyfriends and casually insult them ?. Also both Cher and Uea decided to leave their boyfriends at the end. Cher because he felt he's not competended to date Gun and because of his mother. Uea because he couldn't work at the place where boss molests him and needed time alone from King. The difference is King was the one who just couldn't leave Uea alone and didn't stop looking after him until he found him. Gun respected Cher's wish and distanced himself but Cher couldn't live without him and waited till he graduates. Both stories have amazing happy endings and both kept me entertained to the end but for rewatching I'd choose Bed Friend because I just enjoyed this story more. It was even more matured and my type of genre. But I loved the comedy in ABAB more.

Both has
Masked hero

Strong female lead

But LLWJ might feel slower if you watched this first but otherwise will enjoy

The focus in both shows are workplace issues and specifically women in the workplace. Talented intelligent women doing their best in a world that is not so kind to them.

Both are Revenge dramas. The glory is mostly a planned psychological one, while King of pigs is a bloody revenge with a lot of psychological issues and trauma. Both has bullying as roots of their problems.

Both are Republican Era dramas. Both MLs are military leaders with a cold outside/warm inside personality, while the FLs are studying in the medical field and are a little immature and innocent. The couple clash at first.

Both are romances in which the ML travels through time and tries to prevent a tragedy. Both have a similar tone and pacing.

Both involve time travel and loss, with the lead trying to save a loved one. One is a parent child relationship, the other a romance.

Both involve one of the leads traveling back in time due to an object to save the life of the other lead who died in an accident.

Both are about one of the leads traveling back in time and trying to prevent the death of a loved one in an accident.

Both involve time travel.
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Both involve time travel.
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Both involve time travel.
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Both involve one of the leads traveling back in time due to an object and trying to save the life of the other lead who died in an accident.

Both are love stories in which the ML travels back in time and tries to save the FL they loved who died.

Both are about the ML traveling back in time and trying to save the FL who he loved and who died in an accident.