Arnold Kim wrote:

It is said that many of the great real-life masters have such a good
control of their center of gravity that they could just stand and have
someone run into them without even budging.  But this is probably a
legend, and we aare talking about akane, here, not some great grandmaster.

Arnold Kim

So are you going to change it or are you going to leave it to anime
logic? 

to others that have just come into this discussion. read the rest of the
fanfic first. it is definately a good one. Only this part defies natural
laws of combat. Other parts are good in just this part of the fanfic has
something to gripe about.

ps. I had a green belt four to five years ago whay did you get?