Holly Macdonald, dedicated manager of the Merry Mistletoe Mercantile, has always dreamt of running her own Christmas wonderland. When Mary, the beloved shop's owner, passes away, Holly inherits the shop. However, Holly's festive plans take an unexpected turn when she learns that she must partner with Ivy Spencer, Mary's drop-dead gorgeous but grumpy relative, who is indifferent to holiday cheer. Not only must they run the shop together, but they must also share the apartment above the shop - for three months.

Holly and Ivy clash over everything—from the shop's dazzling decorations to how much to give to charity. Ivy, who prefers a no-nonsense approach, is reluctantly charmed by Holly's over-the-top holiday spirit. Holly is pleased to discover that Ivy's personality quirks have an unexpected appeal. Together, they navigate a series of comedic misadventures, including a near-death gingerbread experience, a runaway sleigh, and a Santa flash mob.

As they juggle the holiday chaos together, can Holly and Ivy discover Christmas magic?