The band was formed in late 1999 by bass player Olli-Pekka "Oppu" Laine and guitarist Ilkka "Ile" Laaksomaa.
Soon they were accompanied by a young drummer, Mikko "Junior" Pietinen, and the following year by lead singer Jani "Joãnitor" Muurinen.
In the countryside of the state of Uttar Pradesh in India, people in villages believed an evil disguised spirit called the Mannhai snatched their children at nightfall.
[2] The record includes the song and music video for "Spiritraiser", directed by Tuukka Temonen (former bass player of the Finnish punk/hardcore group Apulanta).
In November 2004 in Tavastia Club, a popular rock venue in Helsinki, Muurinen played his last gig as a member of Mannhai.
During this time Muurinen had lived and studied in Turku while the rest of the band had always maintained their home base in Helsinki.
In the spring of 2005 Mannhai got a new lead singer, Trond Skog, previous vocalist for Norwegian stoner rock band Honcho.
The role of the keyboards stayed behind the rumbling bass heavy guitar sound, with only a hint of psychedelia.
In late 2006, drummer Junior Pietinen left the band to work full-time on his other groups Bleak and Happiness.
Janitor's successor Pasi Koskinen, a former Amorphis member as well, has vocal duties in his other bands Shape of Despair and Ajattara.