Yoichi Takehiko is a human student and class representative sharing a classroom with Mahiro Yasaka, Nyaruko, Kuuko, and Hasuta. He shares a close bond with Mahiro, routinely guiding him through academic hurdles and social dilemmas while serving as a stabilizing anchor amid the unpredictable antics of their otherworldly peers.

Recognized for his level-headed pragmatism and approachable nature, Yoichi operates as Mahiro’s steadfast confidant. His role remains uniformly supportive across the series, devoid of explored personal history or evolving storylines. He features in multiple adaptations, including the *Haiyore! Nyaruko-san F* OVA, consistently portrayed as a peripheral yet dependable figure within the school’s social framework.