penthouse

A penthouse is a huge building with 100 floors; the higher the floor, the higher the status. Rich and powerful people live there.
roles:
Joo Dan Tae's real name is Baek Joon Ki (but no one knows about it). He is rich and very influential and has his own servant who does whatever Dan Tae says.
Sim Suren is Dan Tae's ex-wife, lives on the 100th floor, is the mother of twins (but is only related to Seok Ken). Now Suren loves Logan and he wanted to propose to her a long time ago, but Dan Tae blew up his car and everyone thought Logan was dead, but he survived and there are still burns on his body and they are slowly taking revenge on Dan Tae.
Seo Jin is Eun Byul's mom, the principal of Cheon's school, a rich and glamorous woman. She is also Yoon Chul's ex-wife and currently lives with Dan Tae (but they don't love each other; they are there for some kind of deal Seo Jin proposed, but on camera they appear to be a happy husband and wife).
Ha Yoon Chul is Yoon Hee's first love (he still loves her), So Jin's ex-husband, Eun Byul's dad (but she doesn't love him because he used to help Rona and then disappeared), he used to be a doctor, he's on the same team with Logan and Suren.
Go Sang Ah is Kyu Jin's wife, Min Hyuk's mother, and Kang Ma Ri's best friend.
Lee Kyu Jin is a mama's boy from a wealthy family and a former lawmaker.
Kang Ma Ri is Yoo Dong Pil's wife, Yoo Jenny's mom, Yoo Hee and Song Ah's friend, and used to work in a sauna (like Edalla massage). Now she and her husband are on the same team with Logan and Suren.
Yoo Dong Pil is Kang Mari's husband, Jenny's dad, he's ready to sacrifice himself for them, a former prisoner (he was framed by Dan Tae), now he's also slowly taking revenge on everyone.
Joo Dan Tae (his real name), but he is Zhong Ki - his name was stolen by Dan Tae (Zhon Ki). He used to be in a mental hospital, but Logan saved him, but now he follows Logan's orders just to not go back to the hospital (this is another revenge plan).
Oh, Yoonhee is Bae Rona's mom, Seo Jin's sworn enemy. She used to be poor, but now they live in Hera Palace on the 45th floor opposite Kang Mari. But Yoonhee died and was thrown off a cliff by Seo Jin (there's a complicated story there; anyone who watched will understand).

There's no more room. If anything, please add more characters that are missing here. If you've watched the drama, you can follow the story.