Twins Shion and Mion Sonozaki have been raised separately in order to avoid infighting about who will be the next head of the family. But the girls managed to keep in contact and when Shion escapes her strict school to come home to Hinamizawa, she knows her sister well enough to impersonate her. While pretending to me Mion, Shion befriends Satoshi and develops a crush on him.
This volume goes back to 1982 before Sakoto’s older brother, Satoshi, “vanished.” He’s trying to get out of town to keep him and his little sister from being abused but apparently even thinking about leaving could invoke the infamous curse.
At this point, you’re not given any more of a clue as to what the curse is or isn’t. I’m glad to get Shion’s point of view on the Cotton Drifting arc but I’m not down with the rampant child abuse and neglect. Not fun to see. But still an overall compelling series. 3.5 out of 5.