Master Kagaya decided to put all hashira’s(except for Muichiro) in groups of two in a room for 5 days. He saw that a few of them didn’t get along, that’s why he did it. Sanemi was with Giyuu, Rengoku was with Tengen, Shinobu was with Gyomei and Obanai was with Mitsuri.

(Your Obanai)

Mitsuri: “Kyaaaa~! I’m so happy we get to be together, Iguro-san~!”