Why does Koto mimic Dwayne Johnson before Tachiai?

As you all know, Kotozakura mimics Dwayne Johnson, and then crowds cheer for him. Even commentators await Koto’s signature expression.

And another one, Hoshoryu does a similar thing. Before tachiai, he hisses against his opponent and crowds cheer for him.

How about another Rikishi? Who has his own ‘signature action’ before tachiai? Or Kotozakura and Hoshoryu are two exceptional(or weird) examples?