Three-part OVA chronicling a story taking place before Chise meets the Magus.

Part 1:

Chise is the student and future bride of the Thorn Sorcerer, Elias. They receive a package from Angelica in London: mostly textbooks, save for one special book.

Part 2 & 3:

The magician of the forest invites Chise into his library. Chise is reluctant at first, but they develop a strong friendship that would have a lasting influence on her.

[Source: Crunchyroll]