Gohon Ude no Mahoutsukai(2020)

Gohon Ude no Mahoutsukai

Lian, a 14-year-old wizard "prodigy", is betrayed by his allies and attacked by a powerful monster, losing his arm in the process.
However, the monster takes an interest in his magic...!?
This is an interracial buddy fantasy between a boy and a monster!

(Source: Shonen Hana to Yume, translated)