[Lummie]

Spoiler for v4:

I'm might not be fully correct but there's a scene where Saras approaches Ayumu with her guards and Sera comes in between and questions his type uttering lines such as:

Sera: お前はラオウの馬かっ!
Are you Raoh's horse! << for anyone who doesn't get the reference, check fist of the north star.

Ayumu:「くっ! ボクはMじゃないんだ。
Kuh! I'm not an M.

Sera「SかMかは……私が決めます。あなたは、ただのM豚ですよ」
Whether you're an "S" or "M".... it's up to me to decide. You're just an M pig.

Ayumu: はい。 ボグはM豚ですし
Yes. I'm just an M pig.



Also between both of them, Saras is more superior in her strength which Sera admits afterwards to Ayumu.