Unnamed Memory, Vol. 4 (manga)

With Tinasha heading back to her tower for a few days, Oscar is left without his guardian"™s supervision. Despite all her warnings to stay safe at home (nagging, if you ask him), Oscar ventures out of the castle to investigate a series of mysterious disappearances in a forest in eastern Farsas. There, he runs into his second witch"”Lucrezia, the Witch of the Forbidden Forest! But is every witch as sweet and helpful as Tinasha"¦?