the hashira had all agreed giyuus haori was horrible looking. Once when giyuu had left his haori at the hashira meeting they took it and did all sorts of things. They bleached it, cut it up, burnt it, drew on it.

they put it in a box and left it on giyuus doorstep.

sanemi, iguro, tengen, rengoku and shinobu all stood hidden nearby to see his reaction