Acid Black Cherry, the solo project of Janne Da Arc vocalist yasu, has announced a temporary hiatus for medical treatment. He will be undergoing surgery to remove a vocal cord cyst.

The cyst was discovered during preparations for his recent tour, which ended on November 2 at the Nippon Budokan. He managed to complete the tour despite the cyst, but he has finally decided to have it removed.

Because of the necessary recovery period, yasu has canceled a concert at the Osaka-jo Hall on December 24. He is also postponing a special event organized for the fans who purchased his new album, "Q.E.D."