Episode 17: Shiori transfers back to Ohtori Gakuen after being gone for quite some time. Juri is tied up in knots, but Shiori seems like a kind person. She seems sincerely sorry for what she had put Juri through in the past, and seemed to try and make friends with Utena and Anthy. However...this all changes once Juri decides to get rid of her locket, and Shiori gets a hold of it. Once you sees she is the one inside...and once she goes to The Mikage Seminar, the real truth comes out. Shiori was always jealous of Juri. She always felt as if she was second best. Juri always had all the love and respect...but now that she knew how Juri felt about her, she felt superior. She felt like she had won. But...Juri had been thinking about her in THAT WAY! Shiori became very angry during her "talk" with Mikage and couldn't stand the thought of Juri thinking about her in that way. Looking at her in that way. So she vowed to get even by revolutionizing the world and really showing her worth. A path had been paved for her...
See her duel lyrics

Episode 28: Tsuchiya Ruka, captain of the fencing team, returns to Ohtori Gakuen after a long absence due to illness and Juri catches his eye...while he catches Shiori's. Shiori must have seen him as an easy target for herself...because as she snooped around his locker, a sword fell out and Ruka approached, assuming that Shiori was the one who had polished it for him while he had been gone. She immediately said that, yes, she was the one who had polished his sword...and the two began seeing each other. Juri told Ruka to stay away from Shiori...and tried to tell Shiori to stay away from Ruka...to no avail. Shiori just called her pathetic. But as Shiori ran to meet Ruka one night, Touga was there in his place, offering Shiori a ride in the Akio car. Once there, she also found Ruka waiting. He promised her the power of miracles. "Kiseki o shinjite..." Once they saw the Ends of the World, the power of miracles would belong to them. Ruka then challenged Utena to a duel, with Shiori as his bride. Of course, Ruka lost the duel and Shiori crashed her car. She then said, "next time, you're sure to win." Ruka informed her that there wouldn't be a next time and that it was partly his Bride's fault that he lost. Shiori tried to defend herself...reminding Ruka that she polished his sword for him everyday...Ruka then informed her, "that was not my sword." He knew she was lying the whole time.

Episode 29: Shiori is screaming across the campus at Ruka...begging him not to go. "Sempai! Without you, I don't have anyone anymore!" But he tells her to let go of his hand and makes his way off. Shiori then begins bawling down on her knees in front of everyone, making a scene. Juri walks away. Later, Utena goes to tell Juri that, if Shiori is really her friend, she should go and talk to her. Juri does just this, but Shiori tells her that she will never ask Juri to help her. She will never do what Juri wants. Later, Ruka lures Juri to the Akio car, and tells Juri that she will do anything he wants. He tells her that she could have the power of miracles...and her wish could come true. She tells him that her only wish would be to free Shiori from him, because Shiori had been calling Ruka, still begging to have him back. Juri is angry that Ruka found it amusing to hurt Shiori that way, as he played back her messages on the Akio car's radio. Once seduced by the power of miracles, Juri challenges Utena to a duel, with Ruka as her Bride. During the duel, Juri's locket is broken from her neck and breaks on the ground. She stumbles and pulls the rose off her own chest. Ruke tells her not to worry as it starts to rain. That evening, you see Shiori follow Juri off campus.

Episode 39: This is the final episode of the series. Shiori's only appearence is at the end, once everyone had "forgotten" about Utena, Juri calls for the next student on the fencing team to challenge her, and Shiori steps forward.

All these synopsis are copyright Cristi, 2000. They are my own words from the episodes I've seen (all but the last one), and, in the case of the last one, from what I've read.