They are factory made export knives made in Japan in the 1980s for foreign importers, most likely U.S.
The top one is essentially a copy of the Cold Steel Tanto, an American creation. Can't be absolutely certain of Japanese origin as I can't see any ricasso markings but I would assume that it is. The bottom one is a tanto with a traditional Japanese motif/wrap treatment. I doubt very much that the mekugi (handle pin) comes out, particularly with the "Stainless Japan" stamping. The hamon is not real, likely bead blasted. I'm pretty certain I've seen both models in back page ads of "Black Belt" magazine back then.
The purpose of these knives was to sell in the US market where the martial arts and ninja craze was fuelling such knife buying. Neither are military and nothing more than a commercial production.
