Hello everybody,

I owned a gunto with number "86913" graved on the habaki and four Kanji on the tang ("YAMADA YASUYUKI" -translation by a Japanese friend of mine) and number "13" below the mei (blade certainly machine-manufactured...).
Would anybody be so kind as to tell me what should be this name (owner, officer, maker, swordsmith... ?).
This tachi wears five petals cherry blossoms (on menuki, saya, fuchi etc). It seems to be an authentic WWII one ; but could it be fake sword too ?
EVERY piece of information is welcome.
I thank anybody in advance.
Greetings from France,