[Kaioshin Sama]

Oh my god, the main rival character absolutely kills me. She hasn't been introduced yet, but....wow....

Spoiler for Amoe Koromo In Vol.4 And Space:

Abandon all hope now, for Koromo has the exact same luck of the tiles as Saki, except she uses it to just completely obliterate every other opponent.

The show seems to be going about 2 chapters at a time so we can probably expect her around episode 6-8.