Engaged to the Unidentified

Alternative: Mikakunin de Shinkoukei, 未確認で進行形
Genres: Comedy Romance Slice of Life Supernatural
Kobeni Yonomori, an ordinary girl, finds out on her 16th birthday that she is betrothed to Hakuya Mitsumine, a boy the same age as her. Hakuya moves in from the countryside and starts living with her, bringing his younger sister who is still a primary school student with him.