There is more than one artist wtih this name: 1. mushroom cloud is a Japanese acoustic pop indie singer. 2. MUSHROOM CLOUD is a melodic death metal band from Denmark. 1. mushroom cloud is a Japanese acoustic pop indie singer. In August 2004, her first pv Sabon (サボン) was released on label site, Galaxy Train. She has a warm and child-like voice, a common trait of Galaxy Train artists. Aoikuuki and shiroi vanilla are the only albums she has released.