S-Rank Monster No Behemoth Dakedo, Neko To Machigawarete Erufu Musume No Kishi (Pet) Toshite Kurashitemasu

Chapter 20
Vol.1 Chapter 19
Chapter 21
Vol.1 Chapter 19
Chapter 21
Elven girl, "Aria" is an adventurer. A small beast with an adorable face embraces Aria's fruitful chest, she decides to keep it as a pet and names it "Tama". At first sight it's just an average cat, but Aria has yet to notice that Tama is a former Knight and that his identity is not a cat, but a young monster of the strongest class "Behemoth".