美女剣士・二人切腹 (1990)

Beautiful Swordswomen: Double Seppuku

The only difference with this one as opposed to the other "entries" - is this one has 2 girls committing suicide, and they are outdoors and wearing samurai style outfits as opposed to Japanese robes or some other "costume". Also, they stab themselves with samurai swords instead of the typical shorter ritual knives...