As the others have said, Gustavo: that is most likely (but not conclusively) a nagauta.
As Patrick and chung said, the white koma and neck look like what we’d expect in nagauta, but they’re not a perfect indicators
It may also be: hauta, jiuta, yanagawa, or kouta shamisen, depending on the specifics of the dimensions.
Take a look at the skin.
Three things stand out to me: the relatively shallow skinning, the sheen of a bachigawa, and the two dots near the middle of the skin.
The distance a skin goes down the dou can tell us a little about the shamisen. We know it’s not a futozao derivative, and we know that the last kawahari was done with aesthetics in mind - or that it’s a fake skin, pre cut and shaped.
The sheen near the neck is a bachigawa. This would tend to rule out kouta shamisen.
You can see two dots faintly, near the middle of the shamisen. This is usually indicative of a cat skin - what you’d be seeing are the nipple holes. However, some dog and plastic skins are marked in a similar way.
I’d also be concerned about any possible neck damage and what the underside looks like, personally.