A frictional piece for a wet frictionally engaging device includes an axis of rotation, a lining support, a pair of friction linings, and a plurality of through holes. The lining support is rotatable about the axis of rotation. The pair of friction linings is mounted on the lining support. The friction linings include respective frictional surfaces that face away from each other. The plurality of through holes extends through the friction linings and the lining support between the frictional surfaces. The frictional piece also includes a plurality of channels each fluidically connecting at least two of the plurality of through holes.