Yahara Sensei was Asai Sensei’s right hand man for many years (and even became second in charge/‘Assistant Chief Instructor’ of the Japan Karate Association). Not to mention, both men were born and grew up in Ehime, Shikoku.
Although Yahara Sensei has evolved and developed his own unique karate (as all elite experts do), you can really see the influence of Asai Sensei in his technique, in particular, his spinning and reverse rotational techniques; aggressive ‘leaping attacks’, and techniques from the ground. Both have a style of unpredictability with techniques potentially coming from anywhere. All in all, an extremely aggressive style of karate focused on ‘attack and finish’. I also believe that Yahara Sensei improved upon the hip action that the JKA advocated, and also radically enhanced 'contraction/expansion'.
The photos on this post (of Asai Sensei and Yahara sensei doing kumite) are from the 1978 publication ‘Jitsugi Karatedo’ (for more info on these books; click here: http://andrebertel.blogspot.com/2008/02/asai-senseis-books.html).