In 'Whose Diary Is It, Anyway?', players take on the role of an eccentric book collector who stumbles upon a mysterious, magical diary at an estate sale. As they explore its contents, they realize the diary belongs to a different character each chapter—each with their own secrets, dreams, and dilemmas. Players must solve a series of intertwined mysteries while navigating the relationships between these characters, leading to an unpredictable and engaging storyline. With each interaction, choices shape the narrative, ultimately exposing the hidden truth about the diary's origin and the owner's fate.