Unaired episode included with the fifth volume of the Blu-ray. The gang goes on a school trip.

On his high school graduation day, Itsuki's cousin, Mahiru, tells him that she's pregnant. Just then, a gate of light emerges and transports the two into the world of Granvania. In this land, Impurities have been causing a disturbance to the Stars, ultimately plunging Granvania into chaos and disorder. And Itsuki, now revealed to be one who is fated to meet with the Star Maidens, is seen as Granvania's last hope and was thus given the task to produce Star Children and combat the impurities. And unless the task is complete, Itsuki may never be able to return home. (Source: Wikipedia, edited)

The story continues where it left off at season 1, but now we start to get to know the people we already know a little more in detail. (Source: ANN)

This two episode OVA retelling of the first Da Capo series with the what if Junichi Asakura were to return Kotori Shirakawa's feelings.