Saikin, Imouto no Yousu ga Chotto Okashiinda ga.

When Mitsuki Kanzaki’s mother remarries, she finds herself with a new stepbrother, Yuya. But shortly after their parents depart on their honeymoon, Mitsuki is possessed by the spirit of Hiyori, a young girl who died without ever experiencing true love. Now, Mitsuki must embark on a series of romantic missions to help Hiyori move on, all while navigating her new family dynamics and the unsettling reality of sharing her own body. This supernatural romance takes an unexpected turn as Mitsuki’s everyday life is upended by Hiyori’s otherworldly agenda. With Hiyori’s spirit influencing her actions and emotions, Mitsuki finds herself in increasingly bizarre and often hilarious situations. Can she fulfill Hiyori’s final wish without losing herself in the process, or will her new, complicated life spin completely out of control?

✦ AI-drafted summary