Kamitsuumi

Kisenosato vs Kotoshogiku, Natsu 2012: Hakuho vs Kisenosato, Nagoya 2012:

Yeah, I agree with the sentiment. It actually seems to be number of yusho where other yokozuna (if any) were kyujo by day 15. I queried for all yusho where Hakuho did not face a yokozuna on day 15: http://sumodb.sumogames.de/Query_bout.aspx?show_form=0&day=15&shikona1=Hakuho&rank1=Y&y1=on&rank2=O-M

You are parsing it incorrectly. 一人横綱 means "lone yokozuna".

After Nagoya, Hakuho said wanted to reach 900 wins as Yokozuna. He was 1 win short at the time.

2:03 and 3:05 you can see Hakuho raising his hand

Goeido vs Kakuryu, Natsu 2014

I thought he has 3 makuuchi uchideshi (Daikiho, Ishiura, Enho) and Hokuseiho is already sekitori.

I'm trying to figure out what Hakuho's retirement payout would be. It looks like: a one-time pension of 15M yen total basho bonus ~45M yen special contribution bonus (apparently ~100M yen for dai-yokozuna) kensho (any guesses to the total amount?) intai-zumo (probably deferred indefinitely)

This was during the second east-west era where all rikishi from Dewanoumi and related heya are put on one side of the banzuke.

I've never seen this usage. Usually ~頃 is used to express uncertainty for an absolute date.

"Seven days" (7日) is expressed differently from "day seven" (7日目). 約 is used with quantities or length of time, but not dates.

Sheer banzuke luck. Kasugao actually got M15w > M7w on a 8-7 for that basho. To be specific: all junior sanyaku were kachikoshi from M1 to M7: Roho and Aminishiki forced two extra Komusubi slots Tamakasuga and Toyonoshima's records were terrible from M8 to M16: a grand total of 4 kachikoshi So there are 4 spots to fill in M1 to M7, and those went to the kachikoshi in lower maegashira. For M8e and M8w the candidates were: Toyazakura 11-4 at J3e Kakuryu 9-6 at J1w Toyonoshima 4-11 at M6w Note that makuuchi stopped at M15w for this basho. So it would have been a toss up by the numbers between Kakuryu and Toyonoshima.

(故郷に)錦を飾る (to wear brocade (back at one's hometown)) is an idiom meaning "to be successful".

In general, these 前 (-zen) 中 (-chū) 後 (-go) suffixes and 上 (originally kami-; ka/kō-) 下 (shimo-) prefixes differentiate the provinces that one large province was divided into. Provinces with these affixes use the same abbreviated form, i.e. the stem + 州 (-shū) , with the exception of Kōzuke. For example, Kazusa Province 上総国 (Kazusa no kuni) and Shimōsa Province 下総国 (Shimōsa no kuni) both split from Fusa Province 総国 (Fusa no kuni). Their shared abbreviation is 総州 (Sōshū).

This isn't correct. "Echigo" and "Echizen" would fall under your "proper name" category, and both provinces indeed share the Esshū "abbreviation".