Changing Status from Tourist to Spousal

I know there're a lot of threads about it, but I will ask again to make sure of the answers.
If I enter Japan with a 90 days visa and I marry my japanese girlfriend, and we try to change my status to spousal of japanese national, Should I give a good reason why not go back to my original country and apply for marriage visa there or even apply for COE?

A lot of users told to just go to the immigration office and give all the papers and prove of our marriage, and just say you want to apply for Change Of Status, but if I don't have any good reason to stay, what should I say or do in this case?

Isn�ft the whole point of �gspouse of Japanese national�h is to allow the non-Japanese spouse to stay with the Japanese spouse in Japan? Don�ft you want to stay together with your wife?? You do have a good reason :)

Just make sure to have all the documents ready so your application for the change will be accepted while you have your Temporary Visitor status valid, and then you can continue to stay until they come up with their decision. Best wishes.

You will have a different issue; getting on your flight to Japan in the first place. If you do not have onward travel, you may be denied boarding because you are not entitled to stay in Japan as a tourist. Better check with your airline about that.

I agree with the friends.

Why would one even consider an option that has you exiting the country?

YOu need to show various documents and either of you must show income proof too. One can enter Japan on tourist visa but getting spouse visa may be difficult by just marrying Japanese girl. If both are not working and dont have sufficient income then its difficult. I saw many examples.

Thank you all for the good answers. I think it's better to get everything ready and just go there with the purpose of changing my status.

Thank you again.

What are these documents you need ready?

Please enlighten, someone who's done this before.

Thanks

Recall that, per law, changing your status from Temporary Visitor to something else is only allowed if you have "exceptional and unavoidable circumstances". Historically, immigration has been pretty lax about this but anecdotal evidence suggests that they have been getting stricter recently. That could be what OP is referring to.

circumstances such as you got married and you want to live with your Japanese Spouse

it's only normal to live together once you're married. rejection is hypocritical if the marriage is genuine. i feel

Yes, my question is about the ''exceptional and unavoidable circumstances'' that they call you need when changing from tourist visa. But I read a lot of cases of normal couples with no exceptional and unavoidable circumstances, that's why I'm a little confused.

The same situation was my before a year came here as a tourist and after apply for change of status and I am 22 year old and my wife is 54 years old but the process gone very smoothly and easy and take 2 months and 10 days we just provided the required documents and we have no long relationship I just mentioned in application that after I came here to Japan we meet and decided to get marry that's all

Mr. X, thank you for you comment. Makes me more relieved. We have a lot of evidences about our marriage. Let's see what will happen.
Thank you all commentors.