I've had these shoes for just over a year and have liked them for the most part. That being said, I wish I had ordered them in a larger size. I'm posting this review to hopefully help others make an informed decision.
I found the AKU Hayatsukis while researching wide mountaineering boots (crampon compatible). I usually wear a men's size 10 wide. I used AKUs sizing chart and measured my mondopoint, which was 27.0, recommending that I order a men's 8.5. That sounded a little ridiculous to me, and the reviews of these shoes vary from some people sizing way up to some sizing down. I ordered a men's 9.5, one full size larger than what was recommended based on the chart.
When I got the shoes, I tried them on with a pair of wool socks that I would wear hiking. The fit seemed pretty good although it was difficult to feel where my toes were in the shoe because these type of boots are intentionally solid. They felt just slightly snug but comfortable and I figured they would likely wear in a bit. I walked around my house with them, up and down stairs, knowing that I wouldn't be able to return them once worn outside.
I've climbed a handful of mountains in the past year using these boots and I wish I had sized up at least by a half to a full size. Ignore the AKU sizing chart! Also, consider that your feet will swell with elevation gain and physical exertion. In addition, I think it's probably smart to get at least a half size up just on account of having a little more room in the toe box for when you're going downhill. This might just be more of an issue because I have wide feet, but if the shoe fits just right going up it might be a little tight going down.
Finally, after my first use of the shoe, I found the outside to have soaked in more water than expected. I contacted customer service about this and they were quick to respond, explaining that even though the outside will get wet, that the shoes will stay dry on the inside as long as I haven't allowed snow or water to get in through the top. This does seem to be the case and as long as I've worn gaiters, the water on the outside of the shoe does not seem to penetrate the inside. The shoes do take awhile to become completely dry after being in snow for a full day, but I think that might be standard for this price point and thickness of mountaineering boot.
I'm debating reordering a larger size of this shoe. They are currently out of the 10.5s and my plan would be to order a size 10 and 10.5 so I can compare and then send one back. That's the recommendation I would have for anyone ordering mountaineering boots online. It seems like a hassle to pay the extra money and then do the return but I think it's totally worth it and will pay off in comfort later. The other boots I'm looking at that are supposedly good for wider feet are the Lowa Alpine Expert II GTX Mountaineering boots. Similar price point and my flipper feet love their Renegades.
