The hashira were gonna play a prank on u and act like there was poison in their drinks and killed them all-

Tengen: has sensitive ears so sits near door playing dead so he can hear when u walk in

Giyuu: actually looks dead-

Shinobu, Sanemi: putting on their best dead look

Mitsuri: positioning cups to look dropped from poison and then plays dead as well

Obanai: Playing along for now

Muichiro: fell asleep-

Rengoku: next to Tengen playing along as well