Samurai were an elevated social class of of warriors who fought for lord in exchange for land and status, similar to knights in medieval Europe. Now, Samurai existed for a period of several hundred years. During the feudal period, Samurai wore the heavy armor with the lacquered leather/metal plates, fastened with silken cords and a kabuto helm. This was a period of time where Japan was divided up into many small city-states thought frequently fought each other constantly for local power.Once Japan was unified, swords and other weapons were confiscated by the emperor and only samurai were allowed to brandish weapons. During this Meiji period, Japan was rather peaceful, there were no long open large-scale wars being fought so there was no need to walk around fully clad in heavy armor. Samurai wore haori and other types of robe. Because they were wearing lighter clothing instead of heavier armor, they wore their swords higher on their waist and due to this started wearing them blade facing up for a higher draw above the waist (as opposed to heavy armored samurai who wore katana with blade-edge facing the ground for a low-mid draw). It's kind of like how knights in the high medieval period wore thick plate mail and a full helm, but during the renaissance period they wore a tabard and tunic with a rapier+buckler.
That said, Samurai in FF5, FFT, FFXI were based on the former, and wore heavier armor (easily coulda been Maiming DPS) but the latter type I mentioned is what FFXI samurai are based on.
Actually he said he was inspired by
Seven Samurai