Can I add Japanese to this add-on language?

[Shitennouji]

Thank you for this add-on.
It works as expected.
For me, it is one of my favorite addons.

by the way,
This add-on is not available in Japanese. It is a barrier for Japanese who dislike applications in different languages.
If possible, I will cooperate in translating into Japanese.

[JustOff]

For this and a few other extensions, I use CrowdIn as a localization platform, and here is my project. You do not need to translate all my add-ons, only those that interest you. You can read introduction for new translators and guide for online editor to understand how it works.

[Shitennouji]

I will correspond according to that specification (CrowdIn).
After a few days, I will start the translation work.

[JustOff]

Please check speed-start-2.1.5b1.xpi, and if everything is alright, I will release it to the public.

[Shitennouji]

Immediately I applied "speed-start-2.1.5b1.xpi" and scrutinized it.
Everything is perfect.
It is complete.

[JustOff]

Did you intentionally leave this string untranslated?

[Shitennouji]

Initially, because it was unknown, I was skipping.
Extra = "付加機能"
I will translate it.