Hi BerberDagger,
according to this...
http://books.google.co.uk/books?id=B...kQ8MZD_Y&hl=en
the difference between a Tanto and Kaiken is how it is worn, if that is the case, the scabbard will probably ID which it is
Could it also be considered to be an 'Aikuchi' another guardless Tanto type knife?
Regards David