Mutyumu (夢中夢, meaning "A dream within a dream" ior "Crazy Dream").
Formed in Japan, 2001 by Hatis Noit (vocals & lyrics) and Ryota Yoda (gutars and compositions) is a Japanese band that describes its own music as a mixture of post-rock, minimal, classical, alternative, and heavy metal.
Due to loss of band members, they went on hiatus as of 2010 stating on their official website "Someday, We'll be back." They made a comeback in 2011 after releasing two remixes for the single "Hope", in digital download only.
It seems that they beginning to work on new album in 2013, as reprted in their Twitter account ( https://twitter.com/mutyumu/status/334162524964519936 )