First, I need to confirm what "Moms Friend" is about. A quick check tells me it's a Korean drama about a woman who marries a wealthy man but then discovers he's involved with her best friend. It's a melodrama with themes of betrayal, revenge, and societal pressures. The "unrated" aspect might be due to content that didn't meet certain standards, but in Korea, most dramas are released with a standard rating, so maybe it's referring to something else. However, the mention of "18" could be a reference to age rating content, suggesting it's for adult audiences, possibly with mature or explicit material.