Sigma Harmonics

Sigma is the teenage son of the wealthy Kurogami family. Though they are known to the public merely as the founders of a business empire, the Kurogamis have a secret. In their mansion in Tokyo, the Great Clock seals away evil spirits known as ouma, and the Kurogami family uses their sound magic to guard the clock. One day, however, the Great Clock's barrier is broken, allowing the ouma to escape. Able to travel through time, the ouma have gone back 50 years in the past and caused devastation to ...