In the process of creating Papillon (Del Rey), Miwa Ueda consulted with counselors to explore the psychology of the twin-sister rivals at the center of her story. Okay, so the experts, as described, kind of sound like Tokyo’s answer to Dr. Phil, but there’s an observant undercurrent to the book all the same.
Ueda introduces withdrawn Ageha and popular Hana, sisters who were raised separately for the first seven or eight years of their lives. Ueda never really explains why the separation occurs, which nags at me. (I always thought the twins in The Parent Trap should have focused their energies on scorched-earth vengeance for their parents’ hideously selfish neglect rather than on trying to reunite them, but maybe that’s just me.) But Ueda is more interested in portraying the sisters’ prickly dynamic than explaining how they arrived at it.
Since Ueda portrays the relationship with feeling and detail, I can mostly overlook the omitted exposition. Ageha is discontent in Hana’s shadow, and she’s been nurturing a crush on a classmate who spent summers in the country near her grandmother’s house. A trainee school counselor (hunky and irresponsible, but amusing all the same) encourages her to pursue the boy and come out of her cocoon in the process. Instead of concocting wacky, demeaning schemes, Ageha begins generally standing up for herself. Her displays of confidence have positive results, earning her new friends.
Hana hates that, of course. She’s used to being the sleek, sparkling city girl in comparison to Ageha’s country mouse bit, partly since Ageha generally played along. It helps Hana maintain her identity by having a drabber mirror image for contrast. So she takes steps to maintain the status quo. But Ueda is generous enough to refrain from making Hana completely horrible, acknowledging that Hana might actually have some feelings for the boy she stole from her sister.
It’s possible that I’m being too generous to Hana based on my distaste for her parents’ past behavior, but I find her and Ageha fairly evenly matched. That balance makes for a more interesting story than a pure underdog portrayal for Ageha. I’m looking forward to future twists and turns, as Ueda has set up a believable dynamic that should be able to generate them without stretching things too far. I admit that I’ll be bitterly disappointed if the sisters don’t go off on Mom and Dad at some point, but for now, I’m content to enjoy the soapy, slightly nasty sister act.
(This review is based on a complimentary copy provided by the publisher.)
The Manga Curmudgeon 
Towards the end of the book there was some vague allusion to Ageha’s having spent the first seven or eight years of her life with Granny in the country having had something to do with her tendency to get horrendous stress-induced stomachaches–or possibly with Hana’s getting upset because it spoiled everyone else’s fun whenever this happened and they had to leave the amusement park or whatever to take Ageha home and put her to bed. Admittedly, this doesn’t seem to jibe very well with the few flashbacks we get of pre-teen Ageha as an apparently healthy country tomboy. But possibly Ueda was trying to imply that standing up to her more assertive sister gave Ageha psychosomatic stomach symptoms even when they were little kids. This might have led the parents to think that Ageha would feel better physically and develop more self-confidence if she and her twin were separated. Of course, it might have worked better if Hana had been the one left with Grandma to develop the additional disadvantage of being an unfashionable country bumpkin…
Huh. I really, really hated this book and found it horribly contrived, particularly for some of the reasons you mentioned (the whole thing about them being separated in childhood really bugged me).