The Kikori are a class of Nihon-Jans who are ordinary people. Kikori is Nihon-Jan for lumberjack. The Kikori help the emperor in The Emperor of Nihon-Ja when the Senshi warriors rebelled against the emperor. Because they were not as skilled as the Senshi in fighting one to one, Will decided that they should work together using shields similar to the soldiers of Toscano.
Despite this they have a deep respect and loyalty towards Emperor Shigeru for the efforts he has made to integrate himself with the lower classes instead of distancing himself from them like previous Emperors have done.
For this reason they are shocked to hear of the rebellion and therefore make the decision to fight alongside Shigeru against Arisaka and his Senshi.