- Main article: Shinto Christian Mythology
As a Child, In order to follow his father's footsteps his life was all devoted to studies, devoid of anime and hobbies. He met a Boy and Kyoji Gekko met at the summer resort during summer vacation. His father is well known in the real estate business. Riku lived in the Mansion in Izumo A maid employed by the Gekko Family who takes care of the Boy. Has knowledge of subcultures like anime and Gundam. After awakening from his incubation tube, he was assigned to be a MS pilot. He later falls in love with Yurin but she was able to guide him out of the colony and even predicted how (foretelling of an attack by a Blaster Elmeth). Once out in space, the pair were engaged in battle by the MSN-09 Emperor Zeong which he was able to defeat thanks to the Gundam's new DODS riffle, however Yurin warned him that a new Kuro Akatsuki model and a Emperor Zeong were heading towards them. In the ensuing battle, Riku could not land a hit on the attacking Gafran and was beginning to become frustrated, but Yurin calmed him down by placing her hand on his and allowing him to predict the enemys' movements, thus defeating it. Afterwards aboard the White Angel, the civilians are picked up by a Federation ship, so Riku and Yurin bid each other farewell, with Yurin giving Riku her ribbon as a token of thanks and as she leaves asks him if they will meet again. Riku, Shinjuku, Taiken, San and Tsuki became Team Kyoji before the Final Battle in Ka Boa Bu. After the Final Battle, Team Kyoji celebrated Kyoji's 200th Birthday at the White Angel.
Paul Gekko ArcEdit
While the White Angel as being upgraded by the AGE System, Riku was reunited with Yurin. While talking about their past and motivations, Yurin opened up wanting to ride the Gundam once again; she liked to float on space and count the stars with Riku showed Yurin her pink ribbon she had given him, likening it as his charm whenever he was fighting. Yurin told him to keep it so it'll continue to protect him. Riku and the rest stayed in Birmings estate for 2 weeks to be teleported to Earth Land by Kaguya Ōtsutsuki.
Birth of Ventus ArcEdit
While taking a breather, Riku heard Atlas Flame's voice and decided to stray away from current battle. The Atlas Flame battles the Fairy Tail Guild in front of Riku at the outskirt of the battlefield. As the two were about to exchange blows, The Revived creature, the Ten Tails came in between them. Riku was utterly shocked and confused to hear the pilot of the Ten Tails, Yurin. Riku wanted to know why Yurin was fighting too and Yurin replied that she only came so she could see him again. Riku felt Yurin's anguish. hen the Juubi, Kaguya Ōtsutsuki and the Black Demon prepares the Bijuu Bomb like it was 67 Years Ago to strike Paul Gekko, Riku activated his X-Rounder ability to summon Natsu Dragneel, Erza Scarlet and Simon to block the Juubi's Special Attack. But Erza sees that Simon is in front of her and that he used his body as a shield to protect her and Paul Gekko. He falls to the ground, confesses his love for Erza, and then dies. Erza screams in anguish as Natsu helps Paul Gekko continues his battle with Kaguya Ōtsutsuki. The Enraged Natsu cuts off Kaguya's Arm containing Black Zetsu. In a surprising turn, Juubi moved in between Motherglare and the Eclipse Gate and took the crash. As the Juubi crash landed and crushed the gate, Yurin could be heard screaming in agony. Yurin told Riku that living is hard. The Gate was shattered into dust and the Juubi was separated from the strange statue before Riku's Eyes. Riku cried out Yurin's name in anguish. But Paul Gekko got the Unconcious Yurin and heal her and Riku was relieved. Riku and Yurin are together once again.
- Yurin Sadamitsu- Love Interest