Newly cured and brimming with confidence, Rudeus resolves to marry Sylphie. Just one problem: he has no idea how marriage works in this world. And when friends tell him any newlywed needs a house, he winds up with a haunted mansion.

Rudeus receives a letter from Paul. The letter explains that Norn and Aisha, Rudeus's younger sisters, have been sent to join Rudeus. Meanwhile Nanahoshi continues her research into summoning magic for a way to return to her original world.

Life is looking up for Rudeus. His sisters are settling in, and he has plenty of time for friends and family... until an announcement from Sylphie and an unexpected letter upend his idyllic school life.

Roxy makes a desperate move to pull Rudeus out of his depression. As the group journeys home, both of them must face their feelings and negotiate the consequences.

Rudeus arrives home, frantic that something may have gone wrong in his absence. But the conversations waiting for him may become disasters in their own right. How can he introduce a new wife to a family still reeling from Paul's death?