|Spoiler Alert: This article/section contains details about future plot lines described in the light novels, not covered in the anime. Do not proceed unless you want to be spoiled.|
|“||It's no good if you don't find the most important thing to you||”|
—Rio Sonogami, to Shido Itsuka
|Eye Color||Deep Pink|
|Novel Debut||Date A Live: Rio Reincarnation (Novel)|
|Game Debut||Date A Live Twin Edition: Rio Reincarnation|
Rio has long plum hair that reaches to her legs. She ties her hair with one single braid and has a bow at the top of her head. Her eyes have a deep color. While in her Astral Dress, Rio wears a lavish pinkish-red dress with a gold emblem on the center. The dress also contains a large robe that reaches her feet.
Rio has a very childlike, yet also kind personality. She restarted Eden in order to try to help Shido, who she views as her father, find happiness.
After Shido came back from school, he suddenly remembers the events that occurred at the end of Rinne Utopia, where Rinne disappeared into his arms. He suddenly hears a voice who asks him if he wants to see his most cherished person again. After which, he begins to black out, and when he wakes up, it was the next day. Much to his surprise, he finds that both Maria and Rinne are still alive, to which the former explains to them that they are in a dream-like world.
After the welcome party for Rinne that night, Shido goes for a walk and he encounters a mysterious little girl. She starts to call him "Papa", which just confuses Shido. After he introduces himself, the girl tells him she knows him, because after all, she knows the name of her "Papa". She introduces herself as Rio Sonogami and asks Shido if he's found his most important person yet. Shido tries to speak with her more, but she runs off. He tries to pursue Rio but heard another voice behind him. He turns to find Marina Arusu there who was overhearing his conversation. She explains that she's trying to find Rio who ran away from her earlier when they were together. After a brief chat with Shido, she leaves.
On the third day, Shido runs into both Marina and Rio once again. Here, he learns that Rio was the one who created this world. She simply wanted to create a world where everyone could be happy. Because she wants everyone to be happy, she was able to bring Rinne and Marina back, despite the fact that they disappeared after the events of the previous 2 games. However, there's a catch with the World they were currently in. It can only last 1 Week before reverting back to the way it was before. Shido realizes what this means, if the World only lasts 1 week, then that means Rinne, Rio, and Marina would also disappear. So they tell Shido that he needs to make a decision and figure out who his most important person is. After which, Shido and Rio make a promise to meet again during the next day.
The next day, Shido meets with Rio at the park. However, Maria followed Shido since he was acting suspicious recently. The three of them spend the day together and return to the park at sunset. Maria and Shido talk for a while, and Maria asks him if he's realized who his most important person is, to which he immediately begins to think about Rinne. Moments later, Rio, who was sleeping in Maria's lap, wakes up. She asks Marina if she's satisfied now, and Shido, who does not understand what she's talking about, looks at Maria, only to find Marina there instead. Marina explains that when she sent Maria to Shido, a small part of herself was sent as well. However, it was just a small piece, not really enough to make her return again. She can only exist in the World that Rio created and that she and Maria share the same body, but are able to switch who is in control. Shido hearing this only confuses him more on the choice he has to make. Since he has time, however, he invites the both of them to come and see Rinne. Rio wants to see her Mama, so she agrees.
When they arrive, Rinne is shocked when Rio starts to call her "Mama". Shido explains everything to her, and they all have dinner. Later that night, Rio tries to get Shido and Rinne to share a bath together, but it doesn't work, so instead, she gets them to agree to sleep together instead. The next morning, Shido wakes up to find that Rio is no longer there.In the True Ending, Shido decides to reject the world that Rio created because he couldn’t find true happiness in that world. Rio and Marina, both of whom were watching over them, appear. Rio doesn't understand why her Papa chose to reject the world she made, a world in which everyone can be happy, and tries to plead with Shido to accept it. Rinne begins to realize something she suspected ever since the previous night, to which Marina confirms it for her. Marina explains that Rio is actually <Ruler>'s Spirit Power, which was hiding inside of Shido. His longing to see Rinne again created the situation they're in now. Marina is glad that Shido chose to reject Rinne because had he chose her, Rio would've made it so that the world would continue forever. Rio still doesn't understand, so Rinne explains to her what it means to truly be happy and she comes to terms with Shido’s decision. Soon after, Rio disappears, and her power as <Ruler> returns back to Rinne.
In the alternate ending, Shido doesn't know what to do when it comes to his decision. Rinne asks him to consider what this would mean for Tohka and everyone as well. Rio and Marina appear, and Rio doesn't understand why it's so difficult for Shido and pleads with him to consider staying here instead. As Rinne begins to understand who Rio truly is, Marina explains that Rio is <Ruler>'s Power, which was hiding inside of Shido until recently. The world she made is one where everyone can be happy, and she begins to question whether Shido doesn't want to be with her. Shido does want to be with her and thus chooses to accept the world they're in.
Rinne asks if he was really okay with this, and asks about everyone else. Shido assures her that everything will be okay, to which she accepts his decision. Marina, however, is a bit disappointed about Shido's decision. Seeing Marina feeling depressed, Rinne tells Rio to do something, to which she agrees. Rio gives Marina her power as <Ruler>, so that she can watch over this World. As Rio disappears, Shido and Rinne promise to see her again. Years later, Shido and Rinne are together, with Rinne being pregnant. Later, she gives birth to Rio and the three of them are together as a family again.
- Light Novel
Powers and Abilities
Astral Dress: Unnamed
Rio inherits Rinne's ability to use Eden. However, unlike Rinne, her Eden is incomplete.
- Like Rinne, Maria and Marina, she doesn't have a number in her name.
- Like with Rinne, her last name "Sonogami" (園神) means "God of the Garden".