Over the past few months I’ve been doing some re-reading of essential karate books and whatnot. I developed a theory that Kusanku/Kushanku/Kanku-dai is the most essential kata in karate as a whole. I have two main reasons for thinking this. Firstly, the etymology of both karatedo and Kusanku/Kushanku/Kanku-dai. And secondly, the clear influence of Kusanku/Kushanku/Kanku-dai on the Pinan/Heian series of kata.