Revision 1

The Underground Laboratory is Dokyo's hidden research facility beneath the Kyoto capital in Onimusha: Way of the Sword, and it is one of Capcom's officially confirmed locations. Capcom describes it directly: "Dokyo's laboratory, situated underground in the capital. The facility houses materials and subjects to be used in the creation of new Genma variants, and is replete with traps to toy with and dispose of any would-be intruders."

Confirmed by Capcom

The Underground Laboratory appears on Capcom's own official location page alongside Kiyomizu-dera Temple, Mount Oe and Yasui Konpiragu Shrine. Unlike those sites, it is not a real Kyoto landmark. It is a facility invented for the story, built beneath the capital rather than reproducing a historical structure.

Dokyo's Work

Capcom's character material describes Dokyo as an entity who "spends much of her time in her laboratory under the capital, engrossed in creating new Genma variants," adding that a glimpse at the facility's eerie nature makes her twisted tastes clear. The laboratory is therefore not simply a location Musashi passes through. It is the origin point for the Genma population overrunning the city above.

Capcom names two specific creations of the laboratory directly. Greater Nue is described as "a Genma created by Dokyo" that assaults its prey with feral, agile attacks and strikes of lightning, and Chijiko is described the same way, as "a Genma created by Dokyo. A grotesque mass of stitched together faces and elastic tentacles." Both confirm the laboratory as a functioning breeding ground for new Genma variants rather than a purely narrative backdrop.

Traps and Hazards

Capcom's description explicitly calls out the facility as "replete with traps to toy with and dispose of any would-be intruders." That framing sets the laboratory apart from the more open, exploratory feel of the city's temples and shrines: it is built to be hostile to anyone who reaches it uninvited, in keeping with a location designed by its owner rather than one that predates the story's events.

Status

The Underground Laboratory's existence, its role as the source of new Genma variants, its ownership by Dokyo, and its trap-filled design are all confirmed directly by Capcom. The facility's size, how many distinct areas it contains, and its position in the overall story structure have not been published.