Saiunkoku Monogatari 2nd Season EP39 - Destined Partners Cannot Be Separated

Shūrei and company return from Ran province back to the Imperial City. Ryūki tells Shūrei that he can't wait forever for her, because as the emperor, he has a duty to get married. He suggests a contest to her: if he can win her over within a certain length of time, then he wins and she will marry him. If he can't, then she wins; he will never ask her again and he will instead marry Jyūsan-hime, who has succeeded Shusui as head of the court ladies. Shūrei agrees and asks him how long the contest will last; the series ends with Ryūki whispering the deadline "Until the Sakura Blooms" into Shūrei's ear.