Introduce a recurring “midnight switch‑eroo” mechanic that adds a playful, tension‑building twist to the roommate fantasy setting. Each night at exactly 12 am, something in the apartment subtly changes—whether it’s a piece of furniture, a locked drawer, or a hidden note—prompting the characters (and the reader) to wonder who moved it and why. The mystery is never overtly explained; instead, the characters discover the change, react, and the story uses the moment to heighten intimacy, humor, or intrigue.