One day, Amano Keita, a fifth-grade student, discovers an unusual capsule toy machine while wandering through town. He decides to buy one out of curiosity, unaware of the mystical encounter that awaits him. Inside the capsule, he meets Whisper, a phantom-like creature, and despite his surprise, impresses Whisper with his calm demeanor and lack of questioning. As a reward, Whisper bestows upon Keita the Youkai Watch, which allows him to see magical creatures called youkai that are invisible to humans. Furthermore, Keita can call upon the powers of the youkai he befriends to aid him in various circumstances. With the aid of Whisper and the Youkai Watch, Keita embarks on a journey to help lost youkai and make new friends along the way.