Suna no Shita no Shirabe

Mishka, a young girl who has lost her home and her right arm, finds shelter in the oasis city of Katanar. There she meets a boy named Chato, who is missing his left arm. Mishka and Chato pretend to be twin siblings, and end up finding a job as servants of Indaris, the son of the city's lord, who lies in bed as an abomination...?

(Source: Shueisha, translated)

Note: Volume 10 of the Kishibe no Uta series.

Collected Stories:
1. Shinintsukai no Yuigon (死人使いの遺言)
2-3. Suna no Shita no Shirabe (砂の下の調べ)