@Flost
It's not a Russian & English pun. It's a Russian & English re-spelling of a Japanese pun.
"Ура" pronounced "ura" (ウラー as transliterated in Katakana in this case), is also 裏 in Kanji, which is the "reverse side," "backside," "opposite side," etc. Given the original novel which this book is referencing is "No Longer Human" (lit. "Disqualified From Being Human" by Osamu Dazai), it's a pun; similar meaning, but different "spelling" as it were. And that's the joke, it almost means the same thing, but it doesn't; because it's just inserting a commonly known Russian word alongside a famous Japanese novel and that common Russian word
sounds like a word in Japanese that has
almost the same meaning as the original famous Japanese novel.
Not a very good English joke, given it's the Russian spelling of a Japanese phonetic pun. But, the reference is still made. A bad way to translate it, but perhaps funnier to an English-speaking audience, would be to have ignored the Russian word altogether and simply titled the book "Human Ass."
