The purpose of this study is to consider Isei of “Ittosai sensei kenpousyo" based on Itai・Doutai and Tai・Yo which are relations of Kegon-thought. Ittouryu is one of Ryuha that had a great effect on modern Kendo formation and “Ittosai sensei kenpousyo" is one of Ittouryu works.

We tried to examine the meaning and content of the term of Isei based on Kegonthought. Because this work is greatly influenced by Jiriron of Kegon-thought. Therefore we supposed Isei influenced by Kegon-thought. Here are the results.

Isei is spouting dynamics from resolute mind. And I and Sei are essentially different in its being but they are also a unit in its function. Here I is Doutai and Sei is Itai and Isei is two as well as one and one as well as two. Therefore there in no time the context. But when we think of Isei in logical reasoning, I is ahead because no I no Sei. Also Isei is based on Jiri. According to this aspect, we must train mind and spirit as well as technique to acquire Isei in Kendo.