In Hatsumi Sensei's book, Ninjutsu History and Tradition, he mentions four striking technique's. These are :

Tenchi Furi - Rising or falling vertical strikes
Yoko Furi - Inwards or outwards horizontal strikes.
Happo Furi - Inward or outward diagonal strikes.
Naka Furi - Forward shooting strikes.

It is my intention to discuss Naka Furi on this occasion. This is illustrated below by Hatsumi Sensei.







 The kusari is held in one hand by a weighted end and gathered up in thepalm of the hand until the other ed is grasped in between the fingers. Youshould now have a hand full of chain with on weight protruding from the palm by the little finger and the other weight from between the index and middle finger.

The kusari can now be thrown forward by punching towards the opponent and pointing the index finger to release the kusari fundo at the opponent, keeping the other end grasped firmly with the little finger. If aimed at the face, it will accomplish the same task as metsubishi (blinding powders). Once the kusari has reached the end of it's flight it may be swung down and back into the opponent in one of the other strikes mentioned above.

I have included below a set of photograph's of Hatsumi Sensei performing a kusari techniques. These pictures are taken from an old issue of an american magazine NINJA, before Hatsumi sensei stopped contributing to it and it went to seed (these photo's are from a 1987 issue)

''This is a lightning fast metsubushi technique. For practice purposes, rather than the kusari fundo, which could be very dangerous, I recommend you use a string with knots tied in at both ends. Please remember as you practice to employ the variety of body movements I explained to you in my earlier article on metsubushi.(Dec/86). (sorry I'll post that article next.) (1) Here Dr Hatsumi assumes the yoko ichimonji no kamae with a knotted string rather than a kusari fundo. (2) As the attacker moves in, draw your left leg diagonally back so that the attackers sword will hit nothing but air. Immediately release the 'fundo' in your left hand, whipping it out at the opponents neck/face area. (3) As you practice you must try many different things. This time throw the 'fundo' in such a manner that it scoops under and around your opponents forearm.''