What is this channel cut in the nakago?

[NotANinja]

I believe the blade is probably o-suriage but I don't know what this channel cut in both sides of the nakago mean? Has anyone ever come across this before? 

 

Many thanks!

[Ray Singer]

Perhaps the individual handling osuriage was considering more of an ubu, Kaga-style of nakago-jiri at one point?

[NotANinja]

2 minutes ago, Ray Singer said:

Perhaps the individual handling osuriage was considering more of an ubu, Kaga-style of nakago-jiri at one point. 

And then presumably just decided against it or gave up? What could have made them decide that I wonder...

[Joseph P.]

I have a wakizashi with a cut in the nakago as well. This one is in gunto fittings.
 

[Rawa]

On 12/17/2025 at 12:22 PM, Joseph P. said:

I have a wakizashi with a cut in the nakago as well. This one is in gunto fittings.
 

Double piece habaki. But it’s kinda to small to fit fully in koiguchi. Saya holds safely?

[Joseph P.]

3 hours ago, Rawa said:

Double piece habaki. But it’s kinda to small to fit fully in koiguchi. Saya holds safely?

Well you know, not really. 
https://photos.app.goo.gl/5kgsGduA5w17fy3W8
Unfortunately the mouth is quite worn, especially at the top. There was a leather strap with a button to keep it secure, but it tore off at some point. It doesn't feel too bad with all the fittings on when it's in there, but definitely not secure.

[Mark S.]

Not to hijack… but a couple pics of the car too wouldn’t hurt my feelings…