Orphaned by war, he was adopted by the hero Genkaku, along with Nanami
, and raised in the small Highland village of Kyaro. Genkaku trained Riou and Nanami to be strong fighters, with Riou's weapon of choice being the tonfa
Riou became best friends with Jowy Atreides
and the two of them went on to join the Unicorn Youth Brigade.
The youth brigade comes under attack, betrayed by their captain, Rowd, in a plan orchestrated by the Highland Prince, Luca Blight
. Luca has the brigade slaughtered and casts the blame on the neighbouring city-state of Jowston as a manufactured excuse to launch an invasion. Riou and Jowy manage to escape by jumping from a cliff in to a river. They are separated and Riou winds up as a prisoner in a mercenary camp run by Viktor
. Here, he is put to work, doing basic labor and errands. Jowy comes to rescue Riou and is himself captured, but the two of them later escape together. They decide to return to Kyaro to reunite with Nanami and meet up with a travelling circus performers, the siblings Rina, Eilie and Bolgan. The group travels through the North Swallow Pass and return to Kyaro. Soon after entering the village, they are arrested by Rowd and are tried and sentenced to death as Jowston spies. Viktor and Flik
appear at the gallows just in time to save them and they all return to the mercenary camp.
At this point, Riou travels to the town of Toto at the request of Jowy. Jowy was found on the river bed by a little girl called Pilika, her family then nursing him back to health. While you are there, Pilika requests that they go to Muse to buy a wooden amulet for her father's birthday. When they return, they find that Luca has ransacked the town, leaving only Pilika alive, who is now rendered mute by the trauma of the events. They are met by Apple
, a young war strategist, who demands they take her to Viktor. They do so, and it's decided that to defend the fort from attack, they will need to use fire spears, but they have fallen in to disrepair. Riou is then sent to recruit Tsai of the Divine Spear, the only man who can fix them. Before the battle, Flik tests Riou to see if he has the skill to lead a company of men in battle. Riou is able to wound him and passes the test. The fort is then attacked but even with the spears functioning, they aren't able to defend it and it's burned to the ground. They all flee and organise to meet up again in Muse, the capital of Jowston.
On the way, they pass through Toto again and Pilika runs off. They find her outside the shrine her father was tasked with maintaining. They enter and Riou and Jowy and transported deep with the Shrine, where they are greeted by the Seeress, Leknaat
, who guides each of them through separate paths to each obtain on half of the Rune of Beginning, with Riou receiving the Bright Shield Rune and Jowy receiving the Black Sword Rune.
Upon arrival at Muse, they are denied entry since they don't have a permit to enter. The party heads to the White Deer Inn and meet the proprietors, Hilda and Alex. Alex has found Sindar ruins in the woods behind the house and offers to let Riou use his pass in to Muse if he helps him find the rumoured treasure in the ruins. After travelling through the ruins and defeating the guardian of ruins, the treasure is found to be a simple herb. Alex throws it away in a rage and then Hilda collapses and falls ill. Nanami then uses the herb to create a medicine that brings Hilda back to health and Alex realises that the ruins have taught him Hilda is his true 'treasure', gratefully handing over his city pass.
Finally gaining entry to Muse, the party reunites with Viktor, who introduces them to the Mayor of Muse, Lady Anabelle. She tells Riou that she has a story to share about his grandfather Genkaku. Riou and Jowy are then secretly tasked with spying on a highland camp to ascertain how well stocked their supplies are. Jowy is captured while escaping, but eventually makes his way back to Muse.
Riou then attends the Hill Top Summit between the all the leaders of the City-State; Muse, Two River, Greenhill, South Window, Tinto and the Matilda Knightdom. Anabelle shares the information about the imminent Highland attack, but the leaders are divided on a course of action. Muse then comes under attack, but is successfully defended. Riou and Nanami go to visit Anabelle to hear her stories of Genkaku, but enter the room to find Jowy has just murdered her. He flees and with her dying breath, Anabelle apologizes for the way the City-State treated Genkaku. Anabelle's assistant, Jess, then walks in on Riou standing over the body and assumes his guilt and runs for help. Jowy then opens the city gates to let the highland army in, so Riou, Viktor and co. all flee again, this time for South Window.
Mayor Granmeyer then asks Viktor to investigate North Window, Viktor's home town, as girls have been mysteriously disappearing around that area. Riou accompanies Viktor and they find that the girls were all taken by Neclord, a vampire who gets his power from the Blue Moon Rune, one of the 27 True Runes. They are unable to defeat Neclord, as he is immune to their attacks. They fall back and Viktor announces that they will need the Star Dragon Sword to destroy Neclord.