Intersect the worlds of Seirei Gensouki, Dragonar Academy, Code Geass, How NOT to be a Demon Lord, Overlord, Undefeated Bahamut Chronicle and Konosuba so that they all take place in the same world, but Rio is the protagonist of not only Seirei Gensouki but also How NOT to be a Demon Lord, Undefeated Bahamut Chronicle, Code Geass and Konosuba. The feudal Japan equivalent seen in the alternate world of Seirei Gensouki is updated to the Greater Japan that conquered Korea, Taiwan and the Pengu Islands, the Sakhalins and the Kurils during the Imjin Wars and the early years of the Tokugawa shogunate seen in canon Code Geass How this happens is this: Rio’s father, the Japanese commoner Zen, dies on an adventuring mission in the Kingdom of Beltrum from Seirei Gensouki, which is the same country as the Arcadia Empire from Undefeated Bahamut Chronicle and the Holy Brittanian Empire from Code Geass in this scenario before Rio’s mother, Ayame realises she is even pregnant with Rio. Ayame passes out from hearing Zen’s death and is brought to the hospital, where she receives blood transfusions and organs from a recently deceased descendant of Napoleon, Marianne Lamperouge from Code Geass due to her organs failing. Due to a series of events Ayame is mistaken for the real Marianne and is courted by the King of Beltrum in canon Seirei Gensouki, who replaces the 98th Emperor of Brittania in canon Code Geass, Charles zii Brittania as Emperor of Brittania in this scenario, Philip Beltrum from Seirei Gensouki, who makes her into one of his wives like what Charles did to the real Marianne in canon Code Geass. Thus when Rio is born, he is born as a Prince of Beltrum due to being mistaken as Phillip’s son and thus this story’s equivalent of Charles’ and Marianne’s son in canon Code Geass Lelouch Lamperouge from Code Geass, although he still has Haruto’s soul from the contemporary Earth reincarnate in him like in canon Seirei Gensouki. This makes Christina Beltrum, the Crown Princess of Beltrum in canon Seirei Gensouki and her younger sister Flora from Seirei Gensouki Rio’s half-sisters in this scenario. Since Haruto and Suzuki Satori from Overlord along with Sakamoto Takuma from How NOT to Summon a Demon Lord were all the same person before Haruto’s death via bus crash, Satori’s Ainz form from YGGDRASIL in Overlord and Takuma’s Diablo form from How not to Summon a Demon Lord made it with Haruto’s soul. Rio is also the same person as Ash Blake from Dragonar Academy, meaning that Ash's little sister, Linda Blake from Dragonar Academy is a Brittanian princess here and the story's equivalent of Lelouch's full little sister, Nunnally vi Brittania from Code Geass due to Linda being Philip's and Ayame's daughter. This of course means Rio can of course ride dragons and since Linda is also in this story the reincarnation of the Dragon Princess Eco from Dragonar Academy, who is Ash's Dragon Pal in canon Dragonar Academy , he is sent to Lautreamont Knight Country [Dragonar Academy's version of post-WW2 German controlled England] in hopes of reclaiming the Brittanian motherland [the British Isles] for Brittania, starting the events of Dragonar Academy. He is then sent to Ashford Academy in Japan, which was never conquered by Brittania in this world under an alias for his protection. The plot revolves around him learning about his powers and dealing with the feelings of the girls around him