This video is of Tegumi drill #11 from the KU (Koryu Uchinadi) curriculum. It has applications from Heian Yondan which makes it suitable for Shotokan practitioners who wish to explore practical kata applications. This drill starts with defending against a haymaker punch, one of the many Habitual Acts of Physical Violence (HAPV) using the opening movement of Heian Yondan. From there, tate shuto uke is used as a 'face wash' followed by a bicep bump (nukite), inside leg kick (I added the yoko geri to the leg to make it fit closer to Heian Yondan (In Pinan Yondan it would be a front kick)), elbow strike and a head butt. It teaches the tori to stay in control of an altercation by bombarding the attacker with a variety of techniques to create disorientation. The uke also benefits in that he/she gets used to training with physicality in a safe environment.
I learned the drill from a friend of mine in the KU. The narration is my interpretation of how it relates to kata, why it is structured the way it is and what we have to gain from this sort of training.