Pretty much a Doom Metal band from japan. They're more instrumental than many would be used to and they have a lot of technical drumming. Though if you are into slow beats that keep your mind at ease, yet they still give you the drive that some metal bands do. Then Boris is your band...certainly not for those that are into mainstream things, they break away from the mold. If you like Acid Bath, Envy, or My Dying Bride then it truly is something you must listen to.
Boris began their career as a drone metal group, with all the indicative markings off such a sound. Their debut album, 1996's Absolutego, clock in at well over an hour in length, yet features only one "song," essentially a collage of shapeless guitar noise—with single chords sometimes streching past the 4-minute mark—and screamed vocals. Throughout their career, they would continue to dabble in this style; their albums Flood and Feedbacker also consist of single epic-length songs, albeit broken into smaller parts, and their The Thing Which Solomon Overlooked series could be descibed as being recorded experiments in the drone genre.
However, the sound that Boris is most associated with today is that of the blues-rock power trio, influenced heavily by late-'60s and '70s groups such as Motörhead, Blue Cheer, and Cream. Boris first made use of this sound on their album Heavy Rocks, which has since become a fan favorite. This album marked a major shift in tone for Boris; comparing Absolutego to Heavy Rocks, it is as if one were comparing two very different bands. Boris has collaborated with fellow Japanese artists Keiji Haino, Michio Kurihara, and Merzbow, in addition to their more famous collaboration with US drone metal band Sunn O))), entitled Altar, which was released on October 31, 2006.
[Information gather from http://en.wikipedia.org/wiki/Boris_%28band%29]