Reasons visa rejection

What are the reasons that a visa can get rejected?
If one bring all documents that embassy ask for, there is still possibility of rejection?
What can be the reason?

Your question implies that you are outside of Japan.
There are several reasons for the visa application denial. Basically, you should give the officer strong reasons that you will go back to your country.
Answer: strong bonds to your country:
You should give the officer in the embassy very strong reasons that you are going to return to your country after visiting Japan.
Example:
-You have a decent job with a good income and have been working for couple of years + married and have a child+ you have your own house in your country+ you have a lot of money saving in your bank account (3000000 Yen)+your age is above 45 would be a plus...
-You have no crime record
If you meet the above requirement, you can actually apply for tourist visa to any other country you want not just Japan.

Yes, but in my case, I am applying for spouse visa.
I want to live in japan.

Indeed, spouse visa can be rejected as well like all other types of visas.
Spouse visa can be rejected for a couple of reasons. For example:
-If officers have strong reasons that your marriage is sham. It means that your marriage is fake like getting married only to obtain visa to live in Japan, the spouse visa can be rejected
-If Japanese spouse cannot sponsor your visa. For example, the spouse does not have a job to support your and herself after coming to Japan, the spouse visa can be denied.
*Japanese spouse or a member of her family must sponsor your visa.
-If there is a huge gap of age between the spouses where it is clear that the marriage is safe.
I can give you this piece of advice which was given to me by a lawyer.
There are many people who met online and wants to get married in the first time they meet the person. This is not good. You should meet at least the person twice in real before the marriage. You should have taken a lot of pictures together to show the embassy...
I highly recommend you to advise your future wife to ask a lawyer for tips to make sure that your marriage will be accepted. I am glad my wife did.

Thank you for the advice!
Yes it's true that if the marriage look like fake, that can be hard to get visa.
My husband have applied for coe for spouse visa for me in japan, he submitted so many documents and pictures of us, to proove it's real, it was accepted.
After he received it, he sent me the coe so I applied for visa at japanese embassy in my country.
At embassy they didn't ask for many documents, just passport, ID , picture, marriage certificate and of course visa application form.
I wonder if it will be fine.

Finger crossed!

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