The famous kdrama starring the popular Geun-Geun couple Moon Geun Young and Jang Seun Seuk, also known as Mary Skipped Her Curfew, aka Mary Stayed Out All Night and in short MMM, M3 or MSOAN is about the story of a girl who finds herself incidentally married 100 days to two men via contract marriage.
Sounds cliched, but this is expected from the same manga author of Full House. The drama unexpectedly turned in low ratings despite a huge amount of anticipation before it aired. Some reasons include bad screenwriting, repetition of plot and not being able to appeal to the middle age group who controls TV viewing. The scriptwriter is changed from episode 11 due to low ratings.
In my opinion, the story is cute enough and expectedly cliched to give fans of light-hearted comedy what they expect. If you're fans of MGY or JGS, give this a go, but skip the middle episodes (8-11) for what many deemed as getting nowhere.
Credits of pictures goes to fans at crunchyroll forum