I can add that to my collection of this guy

Well he's right about the Katana being a useless sword.

All swords are useless if you don't use them right. Likewise, most swords are pretty effective at what they're made to do. The katana, like most swords, was designed as a sidearm. Its primary purpose was to be carried daily as a status symbol and be used for self defense. Japan, as a rule, had low-quality armor, as a result, the katana is optimized for use against unarmored opponents, hence the curved, single-edged blade.

A katana's primary drawback would be that the low-quality iron available in Japan the reason for the aforementioned poor armor meant that they had to use far more laborious, time-consuming production methods than western swords of comparable quality.

The only obvious reason for the mysticism surrounding the katana is that due to the peace and prosperity which marked Japan's Edo period, the samurai had no reason to train heavily with more practical weapons eg: spears, bows, and guns , and thus practiced with the sword that they would most often be fighting with, if they fought at all. Europeans, who had been fighting amongst themselves nonstop throughout recorded history, prepared for wars, not duels, thus the samurai, and their swords might have seemed exceptional because that was what they had been practicing.

tl;dr it's overrated, but far from useless

the mythology around the samurai is that after they finished shooting bows at each other, they charged at each other and sought a worthy foe on the battlefield, and pretty much everybody held 1v1 duels, and if you won, went on to the next one. obviously, with the sengoku jidai, ashigaru fighting in formation, be it with spear or gun made this impractical. but how much truth is there to the honorable battlefield fighting before that?

Korea explains Japanese education

Destroyed.