質問: I've been playing some しりとり recently at and was wondering why no words with を show up. siritori.net suggests there are quite a few nouns starting with を: > > を > をかし > をことてん > をつうじ > をつうじて > をつうじまして > をとおして > をとおしまして > をの > をひてかわ > をめぐって > をめぐりまして > をめぐります > をめぐる > をもちまして > をもって > をろがま > をろがみ > をろがみゃ > をろがむ > をろがめ > をろがも > をろがん > ををがけ > をんなひゃくにんいっしゅ > > > With the exception of maybe を at the beginning of the list, apparently these are all playable nouns in shiritori. There is also a list of words **ending** with を here: . In contrast, jisho.org gives one noun **starting** with を (ヲタ, and even then, it's an abbrieviation of ヲタク or オタク) and no nouns **ending** in を. In a shiritori game with a **normal person**, or even at **competitive** shiritori, does を show up? Are the を words at siritori.net **too obscure** to be valid? (Feel free to add the classical-japanese tag if it's appropriate; I'm not sure if this counts.)
回答: It's because を is not used in post-1946 orthography. All of the をs were changed to おs, for example, おかしい, おとこ. The only reason we use it today is because it was retained in the particle を, but it's not the correct spelling of any dictionary word. (ヲタク is slang.) My 新明解 lists four words that start with を, and they are all grammatical terms relating to the particle. Thankfully no word ends in を so it wouldn't come up (the link you gave to siritori.net shows people's personal names). I suspect most people would play the game as if it were the same as お. I don't know how shiritori was played before 1946.