TV-Series
Description
Mahiro Yasaka begins as an ordinary human teenager fascinated by the Cthulhu Mythos. His life transforms during an alien nightgaunt attack, leading to rescue by Nyaruko, an agent of the Space Defense Agency. This encounter thrusts him into a world populated by extraterrestrial beings inspired by Lovecraftian entities, though depicted without their traditional horror elements.

Physically, Mahiro is tall and slender with gray-bluish eyes and brown hair, typically wearing his school uniform and tie. His appearance holds an unusual allure for aliens, explaining both Nyaruko's instant infatuation upon seeing his profile and the frequent abduction attempts by hostile entities.

Personality-wise, Mahiro is rational, peace-loving, and tolerant, though easily exasperated by chaos. He clings to normalcy amidst the absurdity surrounding him. When sufficiently provoked—especially by inappropriate alien advances—he reacts with unnaturally swift fork-throwing attacks. No alien can dodge these strikes, hinting at latent abilities inherited from his mother, Yoriko Yasaka, a seasoned monster hunter who shares this proficiency but carries more forks.

Initially resentful of the alien presence, Mahiro actively tries to expel Nyaruko, Kūko (a Cthughan alien infatuated with Nyaruko), and Hasuta (a Hasturan alien attracted to Mahiro). He gradually accepts their coexistence in his home and school. While frequently annoyed by Nyaruko's aggressive romantic pursuits, he harbors an underlying attraction to her human form. This tension culminates in several kisses, including an on-screen kiss in the final OVA, *Nyaruko F*.

His development involves navigating complex relationships: Nyaruko's persistence, Kūko's shift from hostility to friendship, Hasuta's affection, and human classmate Tamao Kurei's unrequited feelings. Mahiro demonstrates kindness, such as aiding Hasuta in distress, and exhibits unique traits like perceiving and resisting space-time fluctuations—a skill later pivotal in certain events. Body-swapping incidents with Nyaruko further challenge his composure, exposing him to her perspective.

By the series' conclusion, Mahiro's tolerance evolves into guarded affection, particularly towards Nyaruko. His maternal lineage as a descendant of "deity hunters" clarifies his combat reflexes. His role expands beyond passive protection to active participation in resolving extraterrestrial threats, leveraging his strategic rationality and unique fork-throwing prowess.