The mum was on basically everything, from rifle to battleship. It was seen as an extension of the emperor himself, loose it and you cut off the finger of the living god. Really in a nutshell that is what it is.
GENERALLY speaking the mum is not the end all and be all that so many casual people think that it is. It being "struck" is just the sign of a "bulk" surrender. The mum intact is (again GENERALLY) thought to be a battlefield pickup, but just as likely could come from a small stash of surrendered arms before the end of the war.
Again I suggest heading over to the rising sun section on gun boards, here you will learn the real in's and out's of this area of collecting this stuff. They have sub sections on just about everything military, as well as most "old" stuff.
Yes it's Emperor's flower and seal of the Japanese Gov. . You are correct about battle field pickups and such .
I've a very close Friend who has no less than 60+ Arisaka's and perhaps 250+ Mauser K98's and other flavors .
Know it took #5 ,24 ft. enclosed trailers ,with custom built shelves racks down each side and they're
fronts ,including the #3 aisles full length down the centers of those trailers , so as to Move his Military collection !. Flags helmets bayonets ammo uniforms and of course Weapons . I shutter to even venture a guess as to the shear #'s he has . He began in earnest around 1959 collecting ALL manner of Military collectibles WWl and WWl . He's 10 years MY senior and his folks fled Germany in 1938 . A self taught gunsmith ,being an ACE mechanic he was ALWAYS very adept at MAKING whatever was necessary .
I myself have Samurai Katana blades as well as Officers sword but MY most prized possession besides a infamous Drilling in unusual caliber is
daishō aka A pair of genuine 15-16 Th. century Samurai swords . The Lady I got My .222 Remington 722 from ,was a Estate and Yard sale scrounger of sorts . Anyway She came across a Lady who's husband long deceased was on Iwo Jima and had # 4 Swords in her closet .
She knew Nothing about them nor did the other Lady ,so I offered to research them for her . I speak a little Japanese and can also depict a few words from using hiragana, katakana and kanji
. I also have Friends who are Japanese ,so what I didn't know they did .
One sword was extremely old and very valuable , a famous fellow in Los Angeles made an offer for the Swords . I informed the Lady of his offer and also gave her as much info as possible so she wouldn't get ripped off by some con artist . She asked why I had told her of their value ,when I could have bought them for Peanuts . I explained I wasn't a thief and BAD things happen to people who deceive others for their personal gain .
Well she contacted the fellow in Los Angeles ,they talked . She hung up and handed Me the Pair of short and long swords ,smiling from ear to ear . I offered to pay what I figured they were worth . SHE refused MY offer and said their MY GIFT TOO YOU . So I've treated them as such since acquiring them .
The Lady didn't know anything about how her husband got them ,only he did send them to her while still in combat with instructions where to put them . She also had a K98 which I did Buy from her in the same closet . According to My friend who is the scrounger ,she and her daughter went on a very nice cruise shortly after the sale of that one sword .
All I can tell you is the blade was signed superb folding of the Damascus steel and the handle was Mother of Pearl inlaid with a unique tsuba .
Some 20 years later I actually went on a hunting trip Bird shooting in Argentina ,with a group of guys and he was one of them who was invited by a friend of My friend . He explained that sword was one in perhaps of 10K swords ,from a famous Master blade maker in one of the bloodiest provinces in Feudal Japan from 14-15 century . He turned it over to a Japanese Museum . That blade was just shy of 31" overall .
Mine are around 25" and 35" and the officers sword is longer 39+" with appropriate Rank and sash adornment a WWll issued Kia Gunto with Colonel ranking . I bought that one elsewhere .