If I could ask, is your response that the visa will "come in about 10 days" based on getting the visa AFTER you already have the Certificate of Eligibility?
This is the PDF of the Certificate of Eligibility. You can print it off at Family Mart or another convenience store and prefill it to save about 30 minutes there, but if you make an error or if it wrinkles, they're not too kind on scribbling out and rewriting things in or trying to flatten it, so you will have to redo it.
http://www.moj.go.jp/content/001290114.pdf
As such, it's best to just fill it in at the immigration office as it's not that long and there's someone there to assist you with a question you may have.
The CoE is the form you will fill out (and I forgot, attach a passport type photo that you can get for 1000 yen at any photo booth, usually located outside of all supermarkets) at Immigration and turn in.
Seen as #12 on the
list of visa purposes here.
Necessary documents:
- Application form 1copy
- Photo (4cm×3cm) 1copy
- * A photo that shows the applicant pictured alone.
- * The applicant should face squarely to the front and should remove any hats, caps or head coverings.
- * There should be a plain background with no shadows.
- * The photo must be sharp and clear.
- * The photo must have been taken within three months prior to submission.
- A return-mail envelope affixed with stamp(s) worth 404 yen (for the recorded delivery purpose)
- The supporting documents to be submitted on the occasion of application are shown in Table 3 1 copy
(As applicant sometimes needs to submit document material(s) other than stipulated in the Immigration Control Act Enforcement Regulations, please refer to your regional immigration office or immigration information center.)
- A document that proves the status (if a legal representative or agent submits the application form on behalf of the applicant)
- In principle, documents and materials which have been submitted will Not be returned to you. If you have submitted any original copies of documents and materials, which would be difficult for you to re-obtain, and would like to have them returned to you, please notify us when you file your application.
Reference:
Application for Certificate of Eligibility | Immigration Bureau of Japan Website
Though the necessary documents are listed on the site above, I would still call in to ensure that you have everything so you can make only one visit as opposed to more than necessary (filing out the CoE and turning it in and picking up of the resident card at a later date). Also, due to coronavirus as previously mentioned, they may not be taking walk-ins and you may need an appointment; or, an appointment to just extend your visa as is until they can get to you so that you're legally here until you can apply.
I thought the application (CoE) cost, but I suppose I was wrong. You fill out your CoE and hand in the required documents there.
Once approved, in my case usually within 10-days, they will send you a post card in the mail to go get your resident card from the office that you applied at. That's when you pay the fee with the amount owed written on the postcard (from memory, it was no more than 7000 yen, but bring more cash just in case).
Japan is a whole different world from the US when it comes to immigration. A spouse of a Japanese visa is essentially like a green card, for as long as you're married (you cannot break away from a marriage and stay here like you can in the US with a green card), and is the quickest way of obtaining legal status to live and work in Japan for 1-3 years (some get 1 year at first, others like me got 3 years).
Closer to the expiration of your visa, it's just filing an extension instead, which is even quicker.
Neither a spouse of a Japanese visa nor a permanent resident application needs an immigration lawyer unless you're denied, which won't happen if it's not a sham marriage or they find discrepancies and/or lies.
You will be surprised how quick and painless it is to get—as opposed to, in my case, the months it would take my wife to get a green card in the States, not to mention the $10,000 in lawyer fees—and get once you make the call and take the visit to apply.
For what it's worth, in order to not prove it's a sham marriage, they looked at photos of my wife and I the first time I applied (it's suggested to bring portraits, pictures out and about, etc. to be prepared for this 'unnecessary' documentation).
(I don't even have to wish you good luck, except good luck not getting road rage in this traffic getting there 
)
