In 'Hello, Who's This?', players take on the role of a snarky detective who receives a series of mysterious phone calls from an unknown number. Each call reveals clues about an elaborate conspiracy involving a group of quirky characters—each with their own secrets and agendas. Players must choose how to respond to the callers, unraveling a tangled web of deception, friendship, and betrayals, all while racing against time to prevent a cataclysmic event. The choices they make will lead to multiple endings, immersing them in a world of intrigue and humor.