I’d like to request some editing help from a Japanese release (classical) as I speak none at all and don’t read the script. The track titles are in Japanese and English, and I have so far just entered the English version. If anybody is willing to help with some edits to sort out the Japanese too, I would be grateful. The release in question is
and I have uploaded scanned artwork which shows the Japanese track titles and more. Thank you.
The track titles (on the back cover, at least) are in Japanese and French.
Would you mind if I now rename them to French, now?
The track and movement titles are already in French - which of course is Olivier Messian’s original language for the work. But do check this is OK if you like. Really the only actual English is the spelling of the word “Symphony” rather than “Symphonie” as in some of the other releases in the group.
Oh yes, sorry, it actually looks like the back cover, in fact. I was fooled by that Symphony, it totally changed my perception, and I saw it non-French.
(I’m French) 
Looking at the back cover, I see that there are track titles in both Japanese and French. I am not sure whether it is correct to enter just the French, or just the Japanese, into the MusicBrainz Track titles, or whether one should enter both languages into each Track title.
In the Titles style guideline, section 4 Multiple or split titles, it addresses some specific cases of entities with multiple titles, but not Tracks or Releases with multiple language versions of the same title.
In the Release style guideline, section 10 Language and script, it says,
If several languages are used in the titles, choose the most common language. For releases where there’s an equal mix of two or more languages and hence no obvious answer, ‘Multiple Languages’ may be the best choice.…
If several scripts are used in the titles, choose the most common script. For releases where there’s an equal mix of two or more scripts and hence no obvious answer, ‘Multiple Scripts’ may be the best choice.… For example, a Japanese release with a mix of English and Japanese titles should normally use ‘Japanese’ as the script.
I wondered what existing practice is. When I search for Releases tagged as Multiple languages and multiple scripts released in Japan in CD format I get over 6000 results. I have not looked through many of them. Most have Release Title either 100% Japanese or 100% a Latin-script language. There are a few exceptions, such as 圧倒的多幸感 〜My Gabber is Your Gabba is Your Gabber is Mine〜, but only a few. I did not come across any classical music release which had both Japanese and Latin-script text in the Track Title field matching both Japanese and Latin-script text in the cover art.
Which is a roundabout way of reaching the conclusion, I think that the French-language text you have entered is fine as a first pass. Maybe add an Annotation, with a message to future editors that the cover art shows Japanese versions of the Release Title and Track Titles. Maybe one of them will read that and add the Japanese text.