https://tachiai.org/2020/04/17/toyonoshima-announces-his-retirement/
https://www.japantimes.co.jp/sports/2020/04/10/sumo/sumos-rigid-lifestyle-offers-bubble-protection-coronavirus-disruption/#.Xp3mitNKjUo
https://enacademic.com/dic.nsf/enwiki/6582873
http://yabai.com/p/4296
https://pop-japan.com/culture/on-turning-60-kanreki-and-celebration-of-rebirth/
https://theculturetrip.com/asia/japan/articles/understanding-the-6-ranks-of-professional-sumo/
http://blog.japantimes.co.jp/yen-for-living/who-pays-for-sumo/
https://the-japan-news.com/news/article/0005803419
https://www.japantimes.co.jp/news/2010/06/20/business/who-pays-for-sumo/#.Xp3cZ9NKifU
https://www.japantimes.co.jp/sports/2020/04/10/sumo/sumos-rigid-lifestyle-offers-bubble-protection-coronavirus-disruption/#.Xp-AgdNKjUo

https://www.japantimes.co.jp/sports/2019/01/17/sumo/sumo-101-retirement-ceremonies/#.XptCUy3My8g
https://en.wikipedia.org/wiki/Japan_Sumo_Association
https://www.japantimes.co.jp/sports/2019/03/23/sumo/sumo-101-retired-stablemasters/#.XpoDZi3My8g

Music

"Advanced Japanese Folk" by Audiotoolz

https://freemusicarchive.org/music/Audiotoolz/Progressive_Folk/02_-_audiotoolz_-_advanced_japanese_folk

Under creative commons license: https://creativecommons.org/licenses/by-nc-nd/3.0/

Intro/Outtro music by MARiAN - Tokyo Trap.