The Woman Who Swallowed the Sun

•both have themes about motherhood
•both female lead are strong
•both drama's revenge element are strong
•both mothers who avenges their daughter's death
•both of the mothers' daughters were bullied
•Fake identity and plastic surgery as for the revenge theme in musume no inochi and it doesn't have fake identity for the the woman who swallowed the sun
•Musume no inochi has a partner in crime while the woman who swallowed the sun didn't have someone who supports her but she married the the chairman and starts revenging

Many of the main/major characters are similar to the ones in The Penthouse. Even the general plot is similar to Season 1's plot of The Penthouse. For example, a daughter dying and the mother setting out to avenge the ones behind her death and find the killer. The only difference is that Shim Su-Ryeon is more of a morally grey character (and so is Oh Yoon-Hee) and Su-Ryeon is rich and married to a businessman, while Baek Seol-Hee is a poor, hardworking single mother.

There's a large group of villains against one heroine. And none of them feel sorry- at all. But the heroine may become an anti-heroine, similar to Go Eun-Jo/Hwang Ga-Heun. Stella Jang is also similar to Hwang Ji-Na. Seol-Hee/Lucia also lost her child like Eun-Jo/Ga-Hun because of the villains.