could be the innersole of the shoe aswell. most brands these days are putting softer inners in there sheos to get a more soft "worn in" feel straight out of the box. check your innersoles and see if your putting alot on weight on your middle toes. most ppl with Morton's Neuroma or even a mild case of it do this. maybe a gerneric "supportive" insole. mizuno are a wide brand so i doubt its the width of the shoe but then maybe your tieing your shoes to tight because of that...