When a young Thai actor ‘Neptune’ is secretly photographed by anti-fan while relaxing in an onsen at his close friend's apartment, despite the image being taken during a group hangout – show only him and a male actor from another agency. This drives both fanbase dissatisfaction. Exhausted from work and public scrutiny, Neptune decides to take a chance to relax in Taipei. 
But when arriving at the apartment, Neptune is shocked to discover that the roommate is none other than ‘Kyo’. —an upperclassman he once had a crush on, now a notorious playboy who changes flings like clothes. Worse, Neptune walks in on Kyo mid-romantic encounter with a woman. That night, Kyo jokingly demands he make up for the interruption…by becoming his instead.

Amid this tangled and chaotic relationship, Neptune returns to Bangkok to continue his work—only to find that Kyo has followed him there as his bodyguard and protects him from anti-fans.This is the beginning of a fateful reunion between a star and the sky - Neptune in the Sky.