Niseshi is the eleventh kata in the Seito Shorei system and is the kata learned for sandan level. In English the name means Difficult Victory.
The kata is thought to be from the mid-17th to mid-19th century, developed by an unknown Chinese practitioner or possibly Arakaki Seisho. The version of Niseshi run in the Seito Shorei-ryu system is still found on Okinawa but it is somewhat obscure. It is thought by some to be a pre-WWII version which makes it an important link to antique karate. Alan Rench included it in the Seito Shorei system as a tribute to Master Trias' version of Nandansho that appears in the Pinnacle.
[Handbook of Shorei-ryu Karate Standards, 2nd edition. Jim Brumbaugh, rokudan]