Japanese page is here.
Does the gyoji call out the name of every rikishi the same number of times?
No. When rikishi are receiving strength water, the gyoji calls out their names, either once or twice. For san ‘yaku bouts and the final juryo bout, the names are called out twice with a brief preface. For example, “On that side is Wakanohana, Wakanohana. On this side is Musashimaru, Musashimaru.” If a lower-ranked rikishi is competing in a san ‘yaku bout, he will also be announced this way. All other rikishi have their names called out just once, as in “Mainoumi and Tochiazuma.”
Does the gyoji have anything special to say before the last bout of the day?
The gyoji speaks in his uniquely drawn out phrasing, saying, “The bouts have proceeded thus far, and now we have on that side Takanohana, Takanohana. And on this side Akebono, Akebono. And with this last bout, we end the day’s program.” On the last bout of the last day of a tournament, the gyoji says, “and this is the final bout on the last day.”
* When the emperor is present, the wording is somewhat more polite.
Is a gunbai made to set specifications?
There are no particular specifications, but years of customs have resulted in a more or less standard size. A gunbai is 43 cm in length and has a width of 20 cm. The fanned section is 25 cm long. The gunbai weighs 750-1100 grams.