That was something.
Theres three options in the letter for the army, navy, and airforce, but there is no option to join the air force. Was that on purpose or did you forget to do it? The MC seems like he wants to be an edgelord and somehow avoids execution for disrespecting the Imperial Japanese flag and changing the uniform. Those are big no-nos in any military. I would do more research into more common soldiering if you want to remain accurate.
I'm not really sure where the story will go, or if it is even historically accurate. Maybe provide some pages of basic training? I don't think they conscripted civilians off the street, let them see a military general, and send them off to murder people with swords within a short time period.
I would also raise the maturity rating with the words you used. I don't think PG is a fitting rating for it.
Well I opened the link not expecting much considering you seem to have some kind of irrational fear of capital letters, but was surprised to find that your grammar is actually considerably better when you put some effort into it, so props for that.
As for the story itself, it's kind of unintentionally hilarious. You realize that the Edgelord Contest ended awhile ago, right? Regardless, I did genuinely laugh out loud when I read the emo cringiness of wanting to kill all those faggot Americans and not giving a fuck about the Jews being gassed. I'll be honest, I kind of love it!
As for whether or not you should finish it, honestly, it depends on whether or not you actually enjoy writing it. If you're only doing it to impress people, don't bother, like you said, the person you're trying to impress will probably never see it, so there's no point. On the other hand, if you're writing it because you genuinely enjoy writing it, then definitely finish it. Nothing is a waste of time if you have fun doing it. ^_^
Nothing is a waste of time if you have fun doing it. ^_^