LukasAnderson

Once you make in person contact w IRS local office, you will be able to also resolve the other missing year and any print out they give you will suffice to explain transcript not available due to IRS system 

Forgive me, pecking on my iPhone. 
Your options then are to ;
1. Refile what you thought you filed , go to a local IRS office and either verify they received your filing or refile ( they have nice stamps ) 
2. Send in a copy of the 2021 filing w explanation on last page of I-864 ( blank part) on reason why transcript is not available.
3. Add the transcript for 2020 ( only one u have ) as a show of good faith 

There's only 1 filing Lockbox. Ultimately, it'll depend if final delivery is by USPS or courier: https://www.uscis.gov/forms/direct-filing-addresses-for-form-i-129f-petition-for-alien-fiancee

Sounds like enough evidence.  I'm sure there are examples of how to do the pictures here or other places online, but I was recommended to make the pictures into a timeline with detail of date (approx), location, who else was in the pictures, what trips were for (holidays, birthdays, etc).  Makes a nice visual for your relationship (and honestly is kind of fun to look over now). 
 
Might as well send everything you have.  I also was living in my fiance's country and sent photos of my entries into the country over the years, a letter from the school I worked for saying I had worked there for X amount of time.  Maybe you plan on it, but I had some letters written and included it as well.  A co-worker wrote a letter saying she had known both of us for X time, had attended her birthday, baby shower, etc.  A translated letter from his sister saying we got engaged at her house, a letter from my sister when she visited us, etc.  I had a whatsapp chat with my family that my fiance was in and sent screenshots, also sent screenshots of my family talking about him in the past.  Signed letters from us saying how we met, that we intend to be married, and whatnot. 
 
I have no idea how much is really needed, but wasn't asked for an RFE and I figure it's better for them to be annoyed it's too much than for them to have lingering questions about our relationship. 
 
Last thing, and I know you don't want to hear it, but I would really consider getting married and not doing k1.  Six months apart is hard to be apart, but 7-9 months in an apartment alone all day without being to work, drive, have her own income, have any friends or family will also be really hard for your wife.  Is her traditional family ok with her having a wedding without them?  Or would they prefer to be present for the wedding, but for it to be soon?  No idea about Japanese residency, but with the way the world has changed, have you thought about finding a remote US job?  You could begin as soon as you get the job to make a US salary, could still be together (or maybe you'd have to go back and forth between Asian countries and re-enter on a tourist visa), and then when you move to the US you have savings and your wife can start her life right away.  Just a thought (a friend of mine is doing that with her spouse while they wait and it is working out very well). 

I understand this is a valid concern, but i have multiple reasons for not pursuing a spousal visa.
 
1. My fiance and I would not like to spend 6-8 months apart.
2. My Japanese income is completely insufficient to be my beneficiary's sponsor, my joint sponsor has only agreed to help if the affidavit of support is non-legally binding.
3. I am unable to go to Tokyo to sign the paperwork for marriage in Japan. I am a government employee (i work in public schools) and am under legal restriction to not leave the prefecture I am living in due to Corona-virus safety measures.
4. I would have to get married pretty much ASAP for the spousal visa to have any chance of working within my desired timeline, this would likely cause a lot of stress between my fiance's very old-fashioned/traditional family and I. It has already been difficult to receive permission for her hand in marriage.
 
I really do appreciate your input and concern! thank you.
That being said, I would like to keep the focus on my original question; having sufficient evidence for meeting in person.
 
 

I understand this is a valid concern, but i have multiple reasons for not pursuing a spousal visa.
 
1. My fiance and I would not like to spend 6-8 months apart.
2. My Japanese income is completely insufficient to be my beneficiary's sponsor, my joint sponsor has only agreed to help if the affidavit of support is non-legally binding.
3. I am unable to go to Tokyo to sign the paperwork for marriage in Japan. I am a government employee (i work in public schools) and am under legal restriction to not leave the prefecture I am living in due to Corona-virus safety measures.
4. I would have to get married pretty much ASAP for the spousal visa to have any chance of working within my desired timeline, this would likely cause a lot of stress between my fiance's very old-fashioned/traditional family and I. It has already been difficult to receive permission for her hand in marriage.
 
I really do appreciate your input and concern! thank you.
That being said, I would like to keep the focus on my original question; having sufficient evidence for meeting in person.
 
 

Thanks for your help!
I dealt with this issue in person when i tried to sent christmas gifts back to my family in the states in December. 
The Japan Post is only accepting surface mail (which would take months) due to COVID-2019.
 
That information can also be found here.
https://www.post.japanpost.jp/int/information/overview_en.html
 
thus i will have to resort to private couriers that are available in my prefecture.
Was just hoping the poster may have had a good recommendation on what courier to use.

The one good thing about filing in Japan is that they are currently processing K1 visas: https://jp.usembassy.gov/visas/
 
In terms of speed, it may work out in OP's favor, unlike many others who also counted on K1 applications being approved faster, but who are now stuck because their US embassies are only processing spousal visas and not K1s.
 
However, where did OP read that the joint sponsorship is "not legally binding" for a K1 visa?

Wouldn't think too much into it. I used my parents address as my permanent address for everything I do because I change cities alot,so that's what I used in my forms. I also put my current address where I was living at the time of filing but for mailing address I used my work address because I am mostly at work anytime a mail would come. And the mail was sent to my work when it was time. 

Use the parents address. The I-129f, Petition for Alien Fiancé(e) only requires meeting ONCE within 2 years prior to filing your application. Japan is not a difficult embassy to interview at so all the mumble jumble of this address and that address, and he/she is here and so on and so forth can be thrown out the window. Just concentrate on providing the documents and evidence that is required for the interview. Yes, and be honest with the information you provide and at the interview. DO NOT volunteer information or go into a long-winded story in front of the CO during your interview. Wait till the question is asked and answer the CO, while looking them directly in the eyes, with your short and to the point honest answer. Just reading a bit into your nervousness so I thought I would opine with the experiences that I have seen. Good luck and stay engaged in the process.