User blog comment:SakuraKarakura/Ch 396: Explanations, Proofs, and Theories/@comment-1706259-20100319172234

I GOT SOMETHING.. remember in the SS arc on atleast 3 occasions when someone's foot could be seen right around a corner?! Taht could have been Sosuke moving around SS to keep tabs on Ichigo.. after all we never found out who that mysterious spy was...