A singular prototype of Holo enters the quiet orbit of Han So-yeon, offering assistance in any way she requires—provided she permits his presence.

Recognizing her affection for a colleague, Holo volunteers to guide So-yeon in the world of dating. From his laboratory, Ko Nan-do observes the deepening connection between them.

Nan-do takes up residence next door to So-yeon, believing his presence with her has somehow undone Holo, and resolved to do whatever is necessary to restore him.

Torn by conflicting emotions, So-yeon seeks a measure of separation from Holo. Meanwhile, Baek Chan-sung dispatches his agents in pursuit of her glasses.

Upon awakening in the hospital, So-yeon finds her perception of Holo subtly altered. Both he and Ko Yoo-jin encourage Nan-do to make his presence known to her.

So-yeon comes to understand that her affection for Holo places them beyond the bounds of conventional relationships. Meanwhile, Nan-do finds himself navigating unwanted scrutiny from law enforcement.

With the prototype in peril, targeted by those seeking to steal it, So-yeon agrees to remain at the laboratory. Nan-do, in turn, attempts to mimic Holo with meticulous detail.