Chijoku no Onna Kishi "Orc no Dekisokonai de Aru Kisama Nanka ni, Kono Watashi ga...!!"

In the fertile and vast lands of the Remirisia continent.
On this continent, the Holy Knights of the Remirisia Kingdom and the Demon King’s army have been locked in a long-standing war.
Today, another battle rages in the wastelands, where the elite Silver Hawk Brigade, led by the valiant knight Mildred, achieves a significant victory.
As both armies begin to withdraw, Orurogin Break, the leader of a group of weapon merchants known as “Salvagers,” arrives to scavenge the battlefield as usual. Suddenly, Mildred appears in a panic.
“Damn it…! Where is the princess?!”
Orurogin, who happens to overhear that the princess of Remirisia has gone missing, hatches a plan. He spreads a false rumor that he has the princess in his custody and sends a fake ransom note demanding that Mildred obey his orders if she wants the princess returned safely.
Believing the threat, Mildred shows up.
“Become my lover for a month, and I’ll return the princess.”
Bound by her unwavering loyalty, the noble knight is deceived and forced to endure a month of shame and humiliation…

[Translated from dlsite]