Joon is a talented artist who struggles with mental health issues and lives with her protective older brother, Benny. They share a close but complicated relationship, as Benny feels responsible for Joon's well-being after their parents' death. One day, Joon loses a high-stakes poker game against one of Benny's friends, resulting in their new housemate, Sam, a quirky and whimsical young man. Sam's bizarre behavior and mime-like antics initially concern Benny, but soon, he realizes that Sam has a unique way of connecting with Joon, bringing unexpected joy and stability to her life.

As Sam and Joon grow closer, their bond begins to challenge the existing dynamics in Benny and Joon's relationship. Benny is torn between wanting to protect his sister and recognizing her need for independence and companionship. As Joon's condition improves with Sam's presence, Benny contemplates whether to allow their unconventional romance to flourish. With emotions escalating, Benny must navigate his fears and desires for his sister's happiness, while Joon faces her own challenges in her journey toward self-reliance and love.