Fleeing a traumatic childhood, lone mercenary Guts drifts from battle to battle, striking down powerful enemies with his unwieldy sword. After one skirmish, Guts clashes with the mystifying Griffith and his small army known as the Band of the Hawk. The victorious Griffith drafts Guts into his ranks, granting the swordsman a kinship unlike anything he has ever known. Alongside the skilled warrior Casca, Guts helps Griffith guide the band to fame and glory. But as he gains military prestige, Griffith becomes the target of assassination attempts and political schemes. He uses Guts to further his ambitious rise to power, taking advantage of the swordsman's lack of aspiration. Even as he grows closer to Casca, Guts' absence of direction robs him of any sense of belonging. Fostering opposing desires, Guts and Casca fight for Griffith's dream—although fractures forming among the trio threaten to disrupt their world.

Miyo Sasaki is an energetic high school girl who comes from a broken family consisting of her unconfident father and an overly invested stepmother, whose attempts at connecting with Miyo come across as bothersome. Seeing Kento Hinode as a refuge from all her personal issues, she cannot help herself from forcing her unorthodox demonstrations of love onto her crush. While Miyo is unable to get Kento's attention as herself, she manages to succeed by interacting with him in the form of a white cat, affectionately nicknamed "Tarou" by Kento. But Miyo soon realizes that she cannot help Kento with the various problems she overhears in her cat form and is now caught between two tough choices. Will she continue her relationship with him as a cat, or will she reveal her identity and risk what they have in order to help him as her human self?