It features subtitles in many different languages. The restoration quality is in my opinion excellent and Mayuzumi's score is apart from the visuals a major asset.
By the way, the IOC has also uploaded most of the other Olympiad documentaries on their website with the exception of Riefenstahl's two films (see the playlist there). Most of them are not nearly as good as the Tokyo film but they are interesting for historical reasons. For instance, it's quite charming to see how the St. Moritz Olympiad opened in 1948. That one was really on a small scale compared to the hoopla you have now.
By the way, if you know how one can download those IOC films I'd be grateful to learn how it's done. Because I couldn't figure it out myself.
A heavily edited and unrestored version of the "Tokyo Olympiad 1964" is also on Youtube uploaded by the IOC:
There is also another version available that's been restored, unfortunately, most of the prologue has been cut - there might be other cuts that I'm not aware of. That's the cut I've obtained. Compared to the fully restored unedited version, that one is about seven minutes shorter.