In the tenth episode of "My Happy Marriage," Miyo and Kiyoka visit Arata, who turns out to be Miyo's relative. Arata introduces them to his home, the Usuba residence, and explains that Miyo's disturbing dreams are a byproduct of her latent supernatural abilities—traits that apparently run in the family.

Upon their arrival, the duo is greeted by Yoshiro Usuba, Arata's grandfather and the patriarch of the Usuba family. Yoshiro reveals that he is also Miyo's grandfather and suggests that her troubling dreams could be alleviated by the protective aura surrounding their home. However, he warns that the nightmares will return if she does not stay with the family, adding that he knows a way to permanently resolve this issue—though at the cost of Miyo's freedom.

Kiyoka vehement opposes leaving Miyo with the Usubas, declaring that he wants to be her guardian. Arata disagrees, citing past incidents involving supernatural powers as the reason Miyo should remain. To settle the dispute, a duel ensues between Kiyoka and Arata. During the duel, Arata makes it clear that he and other members of the Usuba family possess abilities suited for combating supernaturally gifted individuals, unlike Miyo. In the end, Arata emerges victorious, erects a barrier to banish Kiyoka, and focuses on protecting Miyo.

Meanwhile, after returning home, Kiyoka receives medical treatment from Hazuki. She persuades him to rescue Miyo, but Kiyoka decides to prioritize an urgent matter related to the "Grotesqueries," as Okaito reveals.

At the Usuba residence, Miyo learns from Arata about her power, which he calls "Dream-Sight," enabling her to manipulate or invade dreams. Arata hints that if she gains control over her abilities, she could peer into different time periods. Later, Yoshiro joins the conversation and shares that Miyo's powers were sealed by her grandmother Sumi—a topic he promises to explain further in the future.