Before the modern era, Princess Chizuru Ooshima, who has a love for sweets, diligently prepares for her English proficiency exam. In an effort to keep her focused, Lord Shogun forbids the consumption of sweets in Edo town. Meanwhile, the Mizutani group, headed by Shizuku "Ane-san" Mizutani and the Yoshida group, led by the unpredictable Haru "Harunosuke" Yoshida, are in conflict. Ane-san persistently seeks to communicate with Harunosuke about the opening of a new temple school, but their meeting leads to a forbidden romance that not everyone supports and may jeopardize their happiness.