When he played the Sannan role, Sakai said that the smile he frequently showed was originally a smile to look down on the Tennenrishinryu group but gradually changed to become a caring smile, and this smile emphasized his benign image.
山南役の演技の際、度々見せる笑顔は元々天然理心流一派を見下すような笑顔だったのだが次第に見守るような笑顔に変わっていったと本人も語っており、この笑顔は温厚なイメージを際立たせるものとなった。