Japanese dagger. Aikuchi Kwaiken Dagger with Horimono

A fine example of a Japanese kwaiken dagger mounted in the aikuchi style. This style is characterized by the fittings which do not generally have a tsuba. The aikuchi form is a form of koshirae for small Japanese swords in which the tsuka ("hilt") and the saya ("scabbard") meet without a tsuba ("crossguard") between them.

The word literally means ai ("meeting") + kuchi ("mouth; opening"), in reference to the way the hilt fits directly against the scabbard. Originally used on the koshigatana (a precursor to the wakizashi) to facilitate close wearing with armour, it became a fashionable upper-class mounting style for a tantō (literally, "small sword", nowadays regarded as a dagger) from the Kamakura period onwards.

This particular example is a kaiken dagger mounted in the aikuchi style. The kaiken is a short long, single- or double-edged dagger, without ornamental fittings housed in a plain mount, formerly carried by men and women of the samurai class in Japan. It was useful for self-defense indoors where the long katana and intermediate wakizashi were inconvenient. Women carried them in their kimono either in a pocket like fold or in the sleeve for self-defense or for suicide by means of slashing the jugular veins and carotid artery in the left side of the neck.

This example is in classic kaiken form, but with a fine blade with two carved horimono on each of the single edged blade, which remains in fine condition retaining the original polish and edge.  The horimono inscriptions  reads 開運 and translates to "good luck,"  a classic inscription.  There are no nicks or any visible kizu in the blade.

The blade marked to the smith Kanemitsu, which may refer to smiths in the Koto or Shinto periods.  There were two 19th century smiths with this name, one from Mino was a student of Kaneyoshi and another who was a priest but scholars are not sure where he lived.