It is said that Wado originally had nine kata, and that six were added later to the list that was presented in 1939 to the Butokukai in Japan (Japanese Budo organisation to register Ryuha). The original list from 1939 included Pinan Shodan, Pinan Nidan, Pinan Sandan, Pinan Yondan, Pinan Godan, Kushanku, Naihanchi, Seishan and Chinto. Between 1942 and 1945 six more kata were added: Rohai, Wanshu, Jitte, Bassai, Jion and of course Niseishi. Although all Kata have names and not numbers, the first nine Kata are usually practiced in sequence (with the exception of Pinan Shodan/Nidan/Sandan due to their different level of difficulties), with special importance to Kushanku, Naihanchi and Seishan, followed by Chinto. The Kata that were added later however, do not really have a specific order and you might question their importance to learning the Wado style.
Present day, JKF Wadokai has published a new book "Wadokai Textbook" which shows 10 Kata. It shows the original nine and Niseishi is included as well. During the official technical seminar of JKF Wadokai in Nagoya, August 2015, they explained that they include Niseishi among the nine because of its specific Wado characteristics.
I would like to share the first enbusen of Niseishi, using video to demonstrate the moments and accompany it with pictures and text.
Slide your body forward using Yori ashi and execute Chudan gyakuzuki with Moto dachi as your left arm moves up with the punch naturally.
A common principle, which is present in many Kata, is that after blocking an attack should follow. That is usally a point of view connected to the movement of the arms. In this case, you can connect it to the body movement as well. After moving back to avoid and block, move in and attack. This waving of the body is called Nami gaeshi.
While not raising your knee excessively, pull your heel while maintaining the posture of your upper body as much as possible. Yet, do it in a natural manner.
Learn how to move your body with gravity. Like Nami gaeshi from Naihanchi, there is a tendency of the body to move to the other leg. In this case, the body has a tendency to move backwards prior to moving. Although it would depend on the explanation that you give, it does not make sense to move your body backwards first, if you want to move forward considering there is no reason to go back first.
Slide your body forward using Yori ashi and execute Chudan mae enpi with Moto dachi. Do so by moving the left arm under the right arm first before executing Enpi.
Even though your body moves just a little bit, movement of the body generates energy and makes it possible to use more than your actual body weight. Enpi is an excellent technique to learn how to use Yori ashi and using your body weight in your technique.