Re: does nikyo hurt?
BTW, the street-bar room brawl version of nikka jo is the same as kihon, except instead of grasping his wrist with the off hand, you throw your arm over and use your elbow to lever him down, while your hand protects your face. You can turn away slightly, so he falls toward his free hand, and anything it might be holding. It's pretty reliable.
I mentioned before that if you are in guard, you can roll for Kimura and come up with nikka jo pretty often, if you are in a gym that allows it. You have to be careful, though- I did that to a BJJ guy and it really pi$$ed him off (but it was at the Bullshido Throwdown in Skokie so it was allowable).