As a young child, Takashi Natsume believed his ability to see youkai to be nothing but a curse. Now a high school student, Natsume has managed to heal from his old wounds and form unbreakable bonds with humans and youkai alike. Natsume's newfound friendships—including the one with his spirit bodyguard Madara, nicknamed "Nyanko-sensei"—are often interlaced with his duty to return the names of the spirits written inside the Book of Friends, his late grandmother Reiko's keepsake. While more remarkable youkai reach out to him, Natsume discovers that he still has much to learn about the world that surrounds him.

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.

After years of animosity, the leaders of Osaka's Somei and Tokyo's Miyama yakuza groups have called a truce—by arranging an engagement between their respective grandchildren, Yoshino Somei and Kirishima Miyama. To this end, 17-year-old Yoshino moves to Tokyo to live with the Miyama family and attend school with her new fiancé. Although Kirishima is all smiles and perfectly polite, there is something unsettling about his demeanor that Yoshino cannot put her finger on. Yoshino's suspicions are soon confirmed: despite his manners, Kirishima is a masochistic maniac. He hurts people without batting an eye and also revels in being punished verbally and physically himself. What he wants most is a spoiled and arrogant fiancée who will ruin his life. When Yoshino does not quite meet his expectations, he reveals his true colors and openly insults her. However, instead of running away in fear, Yoshino decides to take revenge by making Kirishima fall in love with her and then ruthlessly breaking his heart.

As the Love Live! Competition draws to a close, Kanon Shibuya takes an offer to study abroad and bids farewell to her friends and fellow members of the school idol group Liella!. Although they will live on opposite sides of the world, both Kanon and the group remain motivated to continue their idol activities. Unbeknownst to Kanon, however, her plans are cut short by Wien Margarete's parents, who request that Kanon remain in Japan for another year so that their daughter can learn from her. While Kanon finds herself in awkward limbo, Wien cannot bring herself to join her once fierce rival Liella! and decides to start a group of her own. Not wanting Wien's determination to go to waste, Kanon joins the new group, recruiting her former group member's sister Tomari Onitsuka in the process. As the newfound unit strives to wash off Wien's controversial past, the new Liella! is also wrestling with the struggles of losing their irreplaceable center.