This is a bonus episode that exists to make you laugh at Yoshida and Haru in Edo-period costumes, nothing more. The art stays sharp, the timing lands, the period-piece jokes don't outstay their welcome. If you finished the series and want twenty minutes of your characters being ridiculous in a different era, this delivers exactly that and asks for nothing else.

In Edo, Princess Chizuru is preparing for a level one English proficiency exam, so the Shogun outlaws sweets to keep her from getting distracted. Meanwhile, the Mizutani and Yoshida groups eye each other warily. Shizuku, known as Ane-san, runs the Mizutani temple school and has permission to found a new school. She wants to tell Harunosuke, the elusive leader of the Yoshida group, since the area falls under his control. She finally meets him by chance, and romance begins to grow between them, though not everyone is pleased. The OVA is a comedic period romance, bundled with the limited edition of the manga's 12th volume.