Haori | Demon Slayer: Kimetsu no Yaiba | Tomioka Giyu

Giyu wears a black standard Demon Slayer uniform,.. Over this, Giyu wears a haori that's split down the middle into two different halves: the right one in a carmine color, and the left one in a geometrically patterned rhombi prints, in green, dark green, orange, and yellow. These haori were later noted to have belonged to his late older sister, Tsutako Tomioka, and his deceased friend Sabito.

Demon Slayer: Kimetsu no Yaiba 
In Taisho-era Japan, Tanjiro Kamado is a kindhearted boy who makes a living selling charcoal. However, his peaceful life is shattered when a Demon slaughters his entire family. His little sister Nezuko is the only survivor, but she has been transformed into a Demon herself! Tanjiro sets out on a dangerous journey to find a way to return his sister to normal and destroy the Demon who ruined his life.

Giyu Tomioka is a major supporting character of Demon Slayer: Kimetsu no Yaiba. He is a Demon Slayer of the Demon Slayer Corps and the current Water Hashira.

(from Kimetsu no Yaiba Wiki)