I like how she has a nice mix of cute and sexy, this combined with Stiel's curvy designs make for a delightful fap. I'd like to see this translated so we can find out the story (at 72 pages it's not your typical excuse plot doujin)
A guy kidnaps Yukari and manages to seal her power away, then sort of forces her to have a relationship with him (she agrees to play along but assures the guy that she'll remember the trouble he caused her). She stays like that for several months and the guy decides to let her go. Yukari by then has fallen in love with him and takes him with her to Gensoukyo. She then offers him her virginity and marries the guy. Her last line (page 56) gets to me, since she says something to the effect of "if I were to make a wish, it would be for this happiness to last forever".
Something to note is that the beginning of the doujinshi is her remembering how she met the guy ("the day I met you was the worst day of my life"). The ending has her commenting on how odd the circumstances that brought them together were, and mentions that she wants to have more children with the guy.
The dialogue justifies the "Yukari is/should be voiced by Inoue Kikuko" thing, too.
@osef1: Yukari is one of those characters that is subject to extremes. You either have stuff like this (there's one doujinshi where a guy tricks her into having sex with him to prove she's an experienced woman instead of a virgin pretending she knows things; she's actually the latter so hilarity ensues), then you have others where she's an ultra slut that fucks guys and then eats them. I think it just comes with trying to work with a character as OP as she is.
The problem isn't the power sealing, the problem is this guy basically continuously raped her for months until she got Stockholm Syndrome. And the author has the BALLS to portray it as something sweet and heartwarming instead of making it clear that the bad guy won, like pretty much every other mind break/corruption story there is. This is just sickening.