northeast (Oriental zodiac), stopping, good radical (no. 138)
艮 centers on the idea of stopping or being still, which in the Oriental zodiac is associated with the northeast direction. The radical sense is the same character used as a component in other kanji.
艮 is an ancient character whose exact origin is uncertain. It is traditionally associated with stopping or stillness and used as a directional symbol for northeast in the Chinese zodiac system.
The shape of 艮 looks like a person standing still with a firm base, representing stopping or being motionless. In the zodiac, this stillness is linked to the northeast direction.
For コン, imagine a con artist stopping in the northeast corner of a room, frozen in place: con -> コン.