Both female leads come to live with the male leads character's family in a employee/employer capacity. Grandfather is same actor in both. Plus cameos from the High Kick series.
Both female leads are hermit stalkers who rarely ever leave the house. Relying instead on binoculars to watch their love from afar.
Both have female leads in a Noona relationship with very persistent, yet adorable male leads.
Both female leads play actresses that have over the top egos and go through reversal of fortunes due to unfortunate circumstances and misunderstandings.