Tenka Touitsu Koi no Ran ~ Shutsujin! Saika 4-nin Shuu

Overview

15th Century Japan is ravaged by constant wars, as the lords of the realm seek to rule the land. Having lost your father in battle, you are working in the restaurant he left your mother and little brother...when an evil magistrate sends your little brother away...to become a poison taster! To save his life, you disguise yourself as a boy and go to the castle in his place...but what awaits you there is so much more! “I'll show you all...my divine rule!” In the Sengoku era...love is the most dangerous battle of all! (Source: Official Website)

Source: AniList