Hayato Ike is a student at Misaki Municipal High School and has been the best friend of the protagonist, Yuji Sakai, since their middle school years. Often called by the nickname "Megane-man" or "Glasses Man" by his classmates, Ike is recognized for his intellect and composed demeanor. He has brown hair, blue eyes, and is rarely seen without his glasses, typically dressed in the standard school uniform.

Ike is level-headed, analytical, and emotionally perceptive, particularly when contrasted with his more oblivious friend, Yuji. His intelligence and dependability make him someone his peers rely on, but he also has a serious and detail-oriented nature, sometimes planning events with an almost comical level of thoroughness. Despite his calm exterior, Ike is prone to severe motion sickness, which leaves him unable to ride buses, roller coasters, or most amusement park attractions.

At the core of Ike's character is his unrequited love for their classmate, Kazumi Yoshida. Despite his own feelings, his loyalty to Yuji and his desire for Kazumi's happiness drive him to act as a supportive confidant, often giving her advice on how to get closer to Yuji. This creates an internal conflict between his selfless nature and his personal wishes, though he rarely acts on his own romantic interest. On one occasion, he invited Kazumi to help him with student council work, but for the most part he prioritizes her friendship and feelings over his own. His emotional awareness often puts him in the position of pointing out to Yuji how his well-meaning but oblivious actions can inadvertently hurt those around him, like Kazumi and Shana.

Throughout the story, Ike serves as a grounding presence in Yuji's increasingly chaotic life, representing the normal, human perspective amidst the supernatural conflicts. His role is primarily within the school setting, where he balances his academic duties as a class and student council member. During the school festival, he is frequently pulled away for council responsibilities by a fellow member, Harumi Fujita.

Ike's significant character development comes at the end of the first season when he decides to stop holding back his feelings. He invites Kazumi on a Christmas Eve date and confesses his love for her. While she does not initially reciprocate his feelings, developments later in the original light novel series suggest that the two eventually begin a romantic relationship. Beyond his emotional growth, Ike demonstrates notable abilities in his analytical thinking and strategic planning, often acting as the voice of reason among his friends and displaying a level of competence that extends beyond just his academic strengths.