Maybe Happy Ending follows Oliver and Claire, whose chance encounter sparks an unlikely friendship. Initially reluctant, they bond over small acts of kindness, shared memories, and a mutual longing for connection. When Claire's battery begins to fail, she proposes a road trip to Jeju Island to see the last fireflies, prompting them to pose as a human couple to avoid detection. The journey deepens their emotional ties, culminating in a tender romance and poignant farewells, as the story ultimately explores love, memory, and the beauty of fleeting moments, even if they don't last forever.