A warp called "Iriki" is set on Wakyu in order to push the arrow along the right side of a bow, and the technique of shooting called "Tunomi (the balance of tension at the root of the thumb)" was developed to take advantage of it.
和弓には弓の右側に位置する矢を真っ直ぐに押し出す為の『入木』という反りが付けられており、射法もそれを活かす為に『角見（つのみ）』の技術が発達してきた。