Traditionaly Goju-ryu relies upon many techniques which involve grabbing and controlling an attacker while striking a vulnerable part of the body. The Kata Seisan is a perfect example of this principle. Seisan literally translates as "thirteen hands". It contains 8 defensive and 5 offensive techniques, both of which involve a change in direction. Hence the name Seisan. The form stresses close range fighting using short punching and low kicking techniques to break through an opponent's defenses. Seisan is an extremely important Kata in Goju-ryu and many hours should be given to it for practice. It has a wealth of knowledge and information contained within it.
I generally don't try and describe kata in writing because it is so hard to visualize; but, since you asked and no one responded let me attempt to describe how seisan is performed in traditional Japanese Gojuryu as promolgated by the Kanzen Gojuryu Karatedo organization of which I am a 4th degree black belt. Keep in mind that such a description as this can not possibly describe the contrast between hard and soft, fast and slow, nor can it describe the coordination of the breathing with the kata performance. In my opinion, all of those things are that which gives gojuryu its uniqueness. But, that having been said...her goes....
1. Off the break, right foot steps forward to sanchin no kamae (sanchin dachi stance) double chudan arms position. 2. Load left hand slowly to chamber, fast face punch with immediate return to chudan arm position in blocking motion. 3. Step with left foot to sanchin dachi, repeat #2 with right hand. 4. Step with right foot to sanchin dachi, repeat #2 with left hand. 5. Double deflection block (right, left) with sweep of right arm to open chudan position reinforced by left hand under tricep. (really difficult to explain the fluidity and grace of this move!) 6. Pivot on left foot, 90 degrees to the left, simultaneously perform a low foot sweep (haku geri) with the right foot while executing an open double chudan arms position (left on top of right at the start, right on the outside during the presentation). 7. Turn back to the original direction by picking up the right foot and pivoting on the left. Simultaneously load both hands into open hand chamber. Hitch step forward into a right side sanchin dachi and execute a double nukite strike to the groin walls with thumb side of hand angled in 45 degrees. 8. Repeat #6 and #7 (second sequence) 9. Repeat #6 and #7 (third sequence) 10. Reach up, label grab, pull in and simo pivot lower body left to strike groin with right hip in original direction. 11. With body facing left, line of attack in original direction, clean off gedan uke block simo w/ rignt kensetsu geri (knee kick) 12. Rechamber kick, pivot on left foot to 180 degree opposite original direction (face backwards) placing right foot in secondary position of left side forward sanchn dachi simo perform left high open chudan kake uke block, right hand to closed fist chamber. 13. Step forward with right foot, perform right high open chudan kake uke block, left hand to closed fist chamber. 14. Step forward with left foot, perform left high open chudan kake uke block (don't turn over hand into grab position this time), right hand to closed fist chamber. 15. Left inside out block/strike (simulating arm break of lapel grab) 16. Pivot 90 degree to right, right foot steps into zenkutsu dachi (forward stance), right eagle claw strike to throat. 17. Twist eagle claw strike 90 degree left, then right in place, two small clockwise circles, double seiken suki punch to solar plexus. 18. Pivot 90 degree to left to gyaku zenkutsu dachi (reverse forward stance), maintain line of attack from #17, righ tetsui uchi (hammer fist strike) to groin. 19. Right leg yoko geri (side kick) to same line of attack. 20. Rechamber right leg, pivot 90 degree on left foot to left so line of attach shifts 180 degrees from #16-19, placing right foot in secondary position of left side forward sanchn dachi while simo left high chudan kake uk w/out çráb. 21. Cross over step with right foot simo left hooking hair grab. 22. Step with left foot to sanchin dachi simo right jodan seiken suki (high punch) with KIAI! 23. Double chudan seiken suki (middle punch) to solar plexus. 24. Right foot swings around behind left to face 45 degree backwards in partial kneeling stance (hmmm...if in the beginning of the kata you faced 12 o'clock this stance faces 7 o'clock) right gedan uke. 25. Staighten up, right mae geri (froît kick) to shiko dachi (horse stance), left hand claw/screen, right upper cut, reposition right mau uraken uchi (frontal backhand strike), reach up downward empi uchi (elbow strike), right gedan tetsui uchi (hammerfist strike), reverse left hand cross body punch, right kensetsu geri (knee kick), place back into shiko dachi stance. 26. Left foot back mawate (turn) 180 degrees into left side forward zenkutsu dachi (forward stance) so as to face the original dirction of the kata. 27. Double lapel grab, pull hands into closed fist chamber with simo right mae geri kekomi (thrust front kick) to chin. 28. On retraction, right foot takes big step backwards and slide into right side back neko ashi dachi (cat stance), right seiken suki with left hand grabing tricep of right arm to reinforce punch. KIAI! 29. Spin out mawashi uke ( double circular block) in place. 30. Closing.