Hidari

Left is a supporting character in Yomi no Tsugai series.

She along with Right form the pair known as "Sayuu-sama" (Lords Left and Right) and she's one of the tsugai that belong to Yuru.

Left is said to be the antithesis of Seal, making her power the natural counter of Seal’s destined owner, Yuru.

(Source: Yomi no Tsugai Wiki)