A unit consisting of Kōichi Yamazaki and Mitsukuni Murayama, who were active at Sony Computer Entertainment (SCE). Formed in 1999.
They are active in Japan and abroad, and gained recognition with the singles So Special and Move On released on UK Frontline Records.
In terms of game music, they mainly provide music under each other's names for Konami 's beatmania series.
Under the name Pentagon, they were involved in SCE games such as arranging for Gran Turismo 3 A-spec and composing and arranging for ICO with Michiru Oshima.