This is the 5368th most frequent Japanese word.
rizin
The word "rizin" is not a standard Japanese term but may refer to "Rizin," a Japanese mixed martial arts promotion company.
In this sentence, 'Rizin' denotes the organization hosting the event or matches being referred.
彼はRizinの試合を見るのが好きです。
He enjoys watching Rizin matches.
Here, 'Rizin' refers to the subject of the article, indicating that it's a notable entity warranting discussion in publications.
最近、Rizinについての記事を読みました。
Recently, I read an article about Rizin.
Here, 'Rizin' is used as a proper noun referring to a specific title, being the name of the MMA tournament.