High school student Taiyou Asano has been socially inept ever since his family died in a car crash. The only person he can properly interact with is his childhood friend, Mutsumi Yozakura—the head of the world's strongest family of spies. Mutsumi's eldest brother, Kyouichirou Yozakura, has been overprotective of her ever since he once rendered her severely injured. His love for Mutsumi is lethal, and Taiyou is his next target. To survive, Taiyou must marry Mutsumi and become a member of the Yozakura family. Thrown headfirst into chaos, Taiyou begins his journey to become a powerful spy in order to protect his wife and uncover the dark secrets of his past and the Yozakura family.

After Rio escapes the capital of the Beltrum Kingdom with his former teacher Celia Claire and his bond spirit, Aishia, he finds himself in a dire situation once again. As it turns out, multiple people from his past life in Japan are suddenly scattered around the new world. Rio rushes to their help, saving a small group and taking them under his wing. To his surprise, one of the rescuees is his old self's childhood friend Miharu Ayase. The newcomers were not the only ones summoned. With old friends and new allies by his side, Rio sets out to locate the other abductees while searching for a way to send them back to Japan. However, Rio never loses sight of his main goal: avenging his mother's death.

On the dusty streets of the castle town Dayah in the Fortna Kingdom, a young orphan named Nina steals for survival. Experiencing one tragedy after another, she has little to hope for in her life. Believing it best for Nina, her closest friend, Saji, hands her over to Second Prince Azure Seth Fortna, who has been searching for someone with unique and intense deep-blue eyes—just like Nina's. The kingdom's princess, the revered Astral Priestess Alisha, has recently died on her way to the Galgada Kingdom, where she was to marry the tyrant First Prince Sett. However, her death is concealed for political reasons, and that is where Nina needs to step in. With nowhere else to go and no one to turn to, Nina assumes Alisha's identity and future duties. But with each moment spent with Azure, Nina feels herself drawn to his warmth, fearing that once she is wed to another, nobody will remain to remember her true self.

Second part of Houkago Shounen Hanako-kun.