You can banish 2 "Six Samurai" monsters from your GY and/or face-up from your field, then target 1 "Six Samurai" monster in your GY, except "Secret Six Samurai - Hatsume"; Special Summon it. You can only use this effect of "Secret Six Samurai - Hatsume" once per turn. If exactly 1 "Six Samurai" monster you control (and no other cards) would be destroyed by card effect, you can banish this card from your GY instead.
That's what puzzled TCG/OCG players back when Secret Six Sams are revealed. They're clearly more ninjas than samurais, and even worse part, according to the lore, Ninjas are supposed to be Six Sams' archenemy lol
Then again, I guess they are secretly Six Sams pretending to be Ninjas to infiltrate the Ninja organization? Would have made so much more sense if they reveal that to be the lore.