The Kei/Yuri submodule was a submodule in Soong-type androids. This submodule was located in the primary system module (torso) of the androids.

In 2365, when Commander William T. Riker was reviewing the technical specifications for Lieutenant Commander Data, this submodule was listed as one of the components in the primary system module. (TNG: "The Measure Of A Man")

This would appear to be one of the many references to Dirty Pair in the series.