[csihar]

Written Japanese does to be a quite a bit more dense than written English, especially if it's heavy in kanji (Chinese symbols), where a single character represents a word or concept and can be several syllables in length when spoken. It's enough of a factor that, back in the 16 bit era when you only had a few MB of storage space to work with, there were several old JRPGs that either needed to have a lot of dialogue cut out in translation to still fit on the cartridge (e.g., Final Fantasy 6), or that were simply never translated at all because it would have been futile to try (e.g., Final Fantasy 5 and Seiken Densetsu 3, according to legend).

However, this page isn't really the best example of that because nearly half the text is actually English loanwords written in katakana (the Japanese syllabary), which is only slightly more dense per character than English, since each character usually represents a consonant and vowel together. So in this case I'd say the Japanese page carries a little more information, but not drastically so. The copy itself is also quite different, though.