Asics re-designed a lot of their shoes and so I had a bit of trouble getting the right size.  My older Asics were a 6.5 and I had to re-order.  The size 7 were still too small and I ended up with a 7.5 to get the right fit in the toe box. I would suggest ordering a half size up and a full size up and return one in order to get a correct fit.