Both are Censored version of Same Sex Original Work.

The women are expressing their love thru giving gifts and acts of service.

Both have great cinematography and discusses the role of women in the society. You Yi being a writer, Yan Wei who owns a photo gallery shop, Jeong Nyeon, Yeong Seo, Juran and all the students of Maeran Gukgeuk being theater actresses.

Jeong Nyeon: The Star is Born talks about yeoseong gukgeuk an artform in South Korea that incorporates pansori and stage performances that features all-women casts and some of them needs to portray a male role. Farewell My Concubine it talks about the Peking opera and some men portray dan (female) roles.

Both stories have implied same sex romance between the characters: Hyerang and Okgyeong, Jeong Nyeon and Juran for Jeong Nyeon: The Star is Born. Cheng Die Yi and Duan Xiao Lu on Farewell My Concubine

If Jeong Nyeon is a pansori genius, Shin Yun Bok is a traditional Korean painting genius. Both are childish but ambitious with their respective craft.
Both shows have homoerotic subtext between women.

Jeong Nyeon character in webtoon was inspired by Kim Tae Ri's Sook Hee in The Handmaiden. Both are women centric and starred by South Korean actress Kim Tae Ri.

Both GLs have been portrayed by T-pop girl groups. BNK48 and CGM48 for the GL movie "The Cheese Sisters" and Cosmos for GL serie "Love Senior". If you are fond of T-pop girl groups please watch both.

The plot is similar where the freshman falls in love with the senior and tries everything to make their seniors fall in love with them. Both are engineering dramas but different flavor since SOTUS is a BL and Love Senior is a GL.

You Yi and Yan Wei dynamic just reminds me of Dao and Koi though two dramas set in different times. These are the same since Dao is also a writer and Koi also protects Dao.

Both women are saving each other against the people around them and they trust one another. It also shows the social class differences of these women but despite of this they learn to love one another.

Both dramas have strong female characters and ahead of their time. Ae shin is a combination of You yi and Yan Wei's traits because, she's a noble lady by day and a freedom fighter by night.

Both have a stunning chemistry between the women and I also noticed that the pairs actresses from TPOTW (Two Moons I pertain to Moon Chae Won and Moon Geun Young) and The Handmaiden (Two Kims pertains to Kim Min Hee and Kim Tae Ri). They have similar surnames which I find it cute.

However, TPOTW has a tragic ending that's why I wished and waited for 8 years for a lesbian movie that defies South Korean stigma against LGBTQ.

Both films features the actresses from the movie "The Handmaiden". It also shows female kinship which often interpreted as 'lesbianism' by some people, aside from that it has some similarities like finding the part of yourself.