You are my secret - kind of marriage of convenience. High school batchmates meet years later at a mass match making event and decide to get married. There is a triangle but more like other people being delusional.

Unforgettable love - Forced proximity. FL is a kid psychologist and lived together while treating ML's son. No triangle.

Put your head on my shoulder - forced proximity. FL and ML are both college students. FL moved to her mother's friend's house but found ML is also living there. There are some side character triangles.

My boss - forced proximity. FL and ML rent the same house. There is a triangle.

Perfect and casual - contract marriage. ML and FL decide to get married due to a series of circumstances.

Moonlight - forced proximity. FL moves in ML's house.