I guess it's time we talk about Tomonori's father Kajinosuke Marui.

Kajinosuke started wrestling in 1982. At only 15, he had managed to rise above the ranks rather quickly.
By the dawn of the Heisei era, Kajinosuke had already reached the coveted Second Division of sumo, meaning he could finally marry the love of his life and enjoy all the benefits of a sekitori.
Kajinosuke had finally reached the rank of makuuchi when a little Tomonori was born. During his time as a makuuchi, Kajinosuke had let himself go, eating more than he should've and as a result almost completely forgetting about his training.
When Kajinosuke hit the 40 year-old mark, his wife began an affair as a result of her husband valuing sumo over his family.
This was the beginning of Kajinosuke's downfall, he was no longer invited to professional bouts, his kōenkai (that's a fanclub for a specific sumo wrestler) was decreasing, and he wasn't allowed to participate in ring entrance ceremonies anymore.
Broken from his divorce and being kicked out of the sumo association, Kajinosuke decided enough was enough and retired from sumo.
Now he spends his toshiyori days training his son and hoping he won't make the same mistakes he made during his career.

Pictured is Kajinosuke being recognized on the street by a former member of his kōenkai while on his way home from his annual waistline checkup, which if you didn't know is a law in Japan ever since 2008.