Long before modern times, sweets-loving Princess Chizuru Ooshima painstakingly studies to pass her English proficiency exam. To keep Her Highness focused, Lord Shogun bans all sweets in the town of Edo. Meanwhile, tensions arise between two powerful factions: the Mizutani group, led by the respected Shizuku "Ane-san" Mizutani; and the Yoshida group, under the leadership of the capricious Haru "Harunosuke" Yoshida.

Ane-san tirelessly tries to make contact with Harunosuke to deliver the news of the founding of a new temple school. But soon after she meets him by chance, romance blooms between the two. However, not everyone approves of this development—and they might stop at nothing to prevent their happiness.