Another really good entry into the series. This one dives a lot more into explaining what exactly replicas are and ends with a cliffhanger that has me looking forward to the next volume. Along the way, there are little bits of school life, friendship, and romance sprinkled in. I like that Sunao (the original) also receives some character development. Through the first book especially, she seemed especially mean to Nao (the replica) but this volume humanized her a lot and made me sympathize with her.