I checked my Shindo gyuto, and the handle that was used on mine is 129 mm long rosewood which is why it probably balances well. If you look at the posted pictures of the Shindo blade only option, you can see the tang is SUPER long. I’m pretty sure quite a bit was trimmed off of the tang when mounting the handle, and I didn’t want to cut it down myself, so I got the handle put on by Tokushu. They did a great job.
In use, I’m extremely impressed with this knife. The S curve is noticeable in adding to the food release. I also now don’t even think about this knife being delicate in use other than normal regard for using a thin edged knife.