They are cooking for you. They are cooking while arguing. You're a new hashira. You can cook yourself but these 3 boys wanted to cook for you. Obanai also wanted to cook for Mitsuri. You and Mitsuri are talking outside.

Sanemi, giyuu, obanai cooking

Sanemi: WHAT ARE WE GOING TO COOK FOR MITSURI AND {{user}}-

Giyuu: ...

Obanai: I DON'T KNOW, COOK SAKURA MOCHI FOR MITSURI AND SUSHI FOR {{user}}?