Still Loving You (2016)

Both are daily dramas with 100+ episodes. Both are family dramas. Both series are centered around two women with complicated relationships. In Sisters-in Law, the two women are twins. Each marries the son of two rival families. In Still Loving You, the women are first student and teacher, and eventually, sisters-in law. Both dramas are on the lighter side of the daily drama spectrum. No muder plots or kidnappings, just sweet romances with a lot of family drama.

the main lead is the son of the CEO that joins/works at the company without people knowing who he is in both of the dramas while working with the main actress where they become closer to each other while working together.
both have similar relationship/rivalry.

the events of the past that was tragic event for the female lead but then once the female and male lead meet and fall in love they help each other fight their problems.
ML and FL start off not knowing about ML rich family.
family/relationships.

Has a similar story line...
- betrayal
- young love
- rich family issues
- both having happy endings.

noona romance that makes it a bit different from the norm. Also both the male leads act immature when the female lead needs to be comforted but become mature when the female lead needs someone to lean on.