The NSK website lists Endo as withdrawing on day 12. I haven’t seen any news reports as to the nature of his injury, but he picked up his 8th loss on day 11, and presumably decided there wasn’t enough at stake to keep fighting hurt. With only 3 wins, Endo will be ranked as a mid-maegashira on the next banzuke. Ozeki Takakeisho will pick up a much-needed freebie and stay on the leaderboard.
Well, at least this explains his poor form. I wonder if he was hurt on Day 1 or Day 2.
He suffered a right knee anterior cruciate ligament he told the Sumo Association and is expected to take four weeks to recover.
https://www.nikkei.com/article/DGXLSSXK40233_U0A920C2000000/
https://news.yahoo.co.jp/articles/6670f8ab280afb4e10cb2d49a4d0420df738d3e5
Basically troubles with his right knee and he got water drained from day 4 or 5, but things got worse. He wanted to fight the Ozeki, but just has no power and can’t bend his knee, so he withdraw. The medical certificate says 4 weeks. His stable master says the best treatment is to not bend the knee for 7-10days and that he won’t be hospitalized.