Kukoro Knight: Seinaru Kishi wa Kuroki Yoroi wo Mi ni Matou

Overview

"Kill! Kill me! I would rather die than suffer such humiliation!" In order to obtain a lasting peace, the human race took the fight to those who were called demons. After being defeated by the Demon Lord, Raguel, a paladin in the hero's party, sacrificed himself by staying behind to allow his friends to escape. He exerted all his strength to challenge the powerful Demon Lord, but.... Raquel woke up to find himself chained in the dungeon, unable to escape. He was prepared for all kinds of torture, but when he met the Demon Lord again, it appeared in the form of a beautiful woman... The Demon Lord's hands forcibly exposed the degrading human nature of the innocent knight. Raquel, trembling with shame, cries out with a noble spirit... The long-awaited manga adaptation of the popular situation drama "Kukkoro Knight☆ The holy knight wears black armor"! (Source: Otomitsu Comics, translated)

Source: AniList