Harumuu

Harumuu is the het ship between Sakurai Haruka and Kusunoki Muu from the MILGRAM fandom.

Canon
Haruka and Muu are close friends. The two seem to get along as both of them are a bit quite and timid in nature. When asked, Haruka states that one of the prisoners he talks to the most is Muu. Muu frequently pays attention to Haruka and in Transformation of a Weakling, Haruka threatens to kill Es if they don't forgive Muu.

Quotes
"I’ve.. changed? Ah, my hairpins and clothes, they’re all things Muu-san picked out for me. How is it? Muu-san is extremely nice, she always pays attention to me."

- Haruka, Season 2 Interrogation.

"It was really scary before, but now I feel at ease. And on top of that… Haruka-kun is really kind! He listens to whatever I say."

- Muu, Season 2 Interrogation

Fanon
Harumuu is a somewhat popular ship in the fandom. It is currently the most popular heterosexual ship including Haruka and Muu. It is mostly rivaled by Muurei.