Koukyuu Chahiden: Chouhi wa Ai yori Cha ga Hoshii

Saika, a devoted "Teaist" (tea enthusiast), stakes her life on all things related to tea—from cultivating leaves to savoring the brew. When she enters what she believes is the Imperial Tea Selection, she unexpectedly becomes a consort instead. Inside the palace, she encounters the emperor, who appreciates fine teas, and uncovers the palace's hidden intrigues. Saika, for whom tea matters more than love or marriage, faces an uncertain fate. What does tomorrow have in store for her...!?

(Source: Shogakukan, translated)