I agree that it could also be Naginata zukuri. There are some features that suggest it might be a copy of another, perhaps older blade—there is an area on the katana ura where the soe-bi has the appearance of having been polished away but I cannot perceive any corresponding irregularity of the blade’s surface that would indicate the removal of a flaw. The Bo-hi lack the curved foot and traditional point of Naginata-hi. There is no sign of machi okuri. If the nakago was shortened it was very long ago. The overall impression is of an old sword that has not been terribly well cared for but has also not been chipped or nicked or significantly corroded. If made as a katana, perhaps early nanbokucho?