Well, 援助交際 is a serious problem, at least it has been for years, so it's not a surprise for me that Wiki covers it extensively
As for the requirements for the female teacher to be a virgin, I think it would be unconstitutional. Maybe there is still such a thing as expectation, at least young females might be expected to keep their personal life secret (kinda similar to idols), but remaining virgins... I don't think even Japan does that. Though they still do a lot of crazy stuff school-wise, or at least have been until very recently
To have robots rolling around, yet still force students to look as similar to each other as possible. But hey, it's just that we are gaijin, we wouldn't ever understand
And as for Japanese and Chinese, Japanese is not modified Chinese, it just uses kanji, which is roughly "Chinese characters adopted for Japanese use" a lot (though it also uses two of its own syllabaries... which also based on Chinese characters... it's complicated and weird when you try to explain it briefly). Basically, Japanese just uses "Chinese" writing (though even the characters are not 1:1 the same as in Chinese) to write out roots of the words, but all the endings (which are not present in Chinese grammatically) and Japanese grammar, interjections, loanwords from Western languages etc. are written in "their own" syllabaries. So, you can actually find words that are written the same in Chinese and Japanese, but that would be mostly because they are either very basic simple concepts — or terms borrowed from Chinese. And even in that case, these words would be read differently, since the Japanese borrowed their reading into their own phonetic system, and it was a long time ago
To give you just one example, 愛 ("love") seems to be using the same character in China and Japan, and the pronunciation is quite close, but 手紙 ("hand" + "paper") means "letter" in Japanese but "toilet paper" in Chinese (though even "Chinese" itself is a generalization since even in China, there are multiple dialects)
To put it another way, Japanese is its own language, but it uses a lot of words borrowed from Chinese, and its writing system includes kanji (which are very close to traditional Chinese characters since they were borrowed from China as well, as Japanese did not have its own writing system, or at least none that was widely used) and two other systems based on Chinese characters as well. It's similar in some ways to English and French actually: English has a lot of French vocabulary, and it uses the Latin alphabet (although it uses it differently), but these are two different languages
Also, I haven't studied this particular aspect, but I would guess that Japanese kanji are much closer to traditional Chinese characters (used in Taiwan but also in some other places) than the simplified ones (used in China itself, first of all)