Asleep under her fish mobile, Ruri awakes from a recurring dream- the sound of water, somehow familiar, yet the context is long forgotten. What is the significance of her dream?
Even though they know the truth about the Jovians, there seems to be little choice but for the crew to keep on fighting, no matter how senseless it now seems. In her spare time, Ruri queries the computer about human history, and discovers that the Earth is no stranger to wars. Will continual conflicts be the pattern of the rest of her life as well?
Ironically, though, there were no wars during the first ten years of Ruri's life, years that she doesn't really remember very well. Time after time she has asked ship's computer Omoikane for information on her past, but it never has anything new to tell her. The records merely state that she was adopted seven years ago, and trained to become the science officer on the Nadesico. What little else Ruri knows of her past comes from her fragmented memories: lessons in maths, science, Japanese and English given from an early age, and shadowy parents encouraging her at every turn with phrases like "Very good, Ruri! Wonderful, Ruri! You're adorable, Ruri!" and "Hooray! Hooray! Hooray!".
At an early age, Ruri soon came to be familiar with the word 'baka' (idiots/fools), a word she soon learned to apply to her ever-cheering parents. But there were others in her life- a blue robot that would play chess with her, and other children with whom she often had lessons with. And something else- a memory of running water, punctuated by splashes. The same sounds that now fill her dreams.
However, it looks like Ruri might finally be about to get the answers she has craved for so long, when a Peaceland envoy arrives on board the Nadesico to see her. A former amusement park, Peaceland is now a neutral kingdom that is also home to a world famous bank, not to mention legalise gambling!
Ruri cannot understand why anyone from Peaceland would want to see her, but the envoy soon explains the situation. Years ago, the king and queen of Peaceland, having failed to conceive an heir, went in for a test tube fertilisation at a famous clinic. Unfortunately, the clinic was blown up shortly afterwards, and the vial containing the fertilised egg was lost. After years of searching, the Peaceland royals finally located their missing child- and that child is none other than Ruri herself!
Later, in her quarters, Ruri decides to find out just what it means to be a princess. After eliminating all anime 'magical princess' data, she settles down to watch some more useful videos and information. After discovering that a princess should always be accompanied by a knight, Ruri puts on a dress and has Akito take her down to Peaceland in his Aestivalis- much to Yurika's annoyance.
At Peaceland castle, Ruri finally meets her family- but they are not the shadowy figures she remembers from her past. Her ebullient father, insipid mother, and quintet of younger brothers are a far cry from what Ruri was expecting, and despite their request that she stay with them, Ruri decides that she needs a little more time to decide what to do.
Almost everyone on the crew wants Ruri to pick something up for them on the surface, so a shopping spree is next on the list. Poor Akito ends up having to carry all the items that Ruri buys, and is more than glad to stop at an Italian restaurant for some pizza. Unfortunately, however, the pizza tastes awful, and Ruri isn't backward about saying so to the chef. Insulted, the burly chef starts tp get violent, and when Akito stops him from hitting Ruri, the chef turns to beating him up instead. Finally, Ruri manages to stop the enraged chef by knocking him out with a shovel, but this only makes matters worse, as the chef's four students come out for some payback. Attempting to protect Ruri, Akito only manages to get beaten up even more.
Ruri apologises for inciting the situation, but Akito merely replies that as her knight, it is his duty to protect her- even if he didn't do a very good job. And, and after all, Ruri was right about the pizza!
Their escapades in Peaceland complete, Ruri has one more place she wants to visit- a fjord in Scandinavia. According to her father, this is where she was brought up, and Ruri hopes that going there will fill in the gaps in her memory.
The school where Ruri was brought up is now little more than a crumbling ruin, but beneath the dust and decay, Ruri can recognise the places where she and the other children once studied together. Wandering through the old corridors, she comes to a closed door with a fish painted on it- and beyond the door lies the ruins of her old room.
As Ruri looks around the place where she once lived, Akito enters, bringing a dishevelled looking man with him. Years ago, the man explains, vials of unidentified fertilised eggs were brought to this place, and he and his colleagues decided that the surviving eggs should be given the chance to grow and live. However, to offset the cost of raising these children, they had to use them as test subjects for their research. Despite the fact that they were breaking the law, the scientists genetically manipulated the children, hoping to create stronger, smarter individuals. They then brought them up using specialised learning programs- these were the classes that Ruri remembers from her past. In Ruri's case, the experiment was a success, but the other children were not so lucky- they all died.
His explanation complete, the man hands over a Peaceland bank card to Ruri- it was given to the school by Nergal to finance her training, but now the money in the account belongs to her. Taking the card, Ruri asks the one question which has been bothering her- what about the parents that raised her?
In response, the man presses a button on a remote control, and from behind, Ruri hears her parents greeting her. Turning around to see them, Ruri sees only a pair of shadowy figures on a computer screen, chanting the same old "Very good, Ruri! Wonderful, Ruri! You're adorable, Ruri!" mantra. The parents that Ruri remembers were never real people- they were a computer program designed to praise and encourage without ever scolding or reprimanding.
Finally realising the truth about the past, Ruri thanks the man for saving her life, before slapping him for all the other things he did to her. Handing back the bank card, she turns away and sits alone in her old chair, only to be distracted by the sound of dripping water- a sound reminiscent of her dreams…
Following the sound of water, Ruri runs out of the room and reaches a locked door. Catching up with her, Akito kicks the door open, and the two step outside. Just outside is a river, and in it schools of salmon are splashing upstream. This is the very image vaguely recalled in Ruri's dreams and memories, the one beautiful and cathartic sight amongst the ugly truths of the past. And now, just like those salmon, it is time for Ruri to return to her true home- the battleship Nadesico.