TV-Series
Description
Kimiaki Shirai is a supporting character who appears as a friend and former classmate of the protagonist, Keitaro Urashima. He is a student at the same preparatory school, or "ronin" (a student who has failed university entrance exams and is studying to retake them), where he is a first-year ronin at the beginning of the story. Physically, he is notably shorter and stockier than his peers, with a round face and a build that could be described as chubby. His most distinctive feature is his large, round glasses, and he often wears his hair in a ponytail. This appearance leads to colorful, if unflattering, comparisons from other characters, such as being called a small, fat hobbit by Kaolla Su.

In terms of personality, Shirai is portrayed as relaxed and good-natured, always seeming to enjoy a good time. He is almost always seen in the company of his fellow student and friend, Masayuki Haitani. Together, the pair serve as a comedic duo, frequently heckling and teasing Keitaro about his struggles with academics and his complicated romantic life. They are sometimes characterized as womanizers, though the more proactive scheming for "babe-hunting" is often instigated by Haitani, with Shirai's reputation perhaps suffering more from guilt by association. Despite their constant ribbing, Shirai is not an unsympathetic character; he demonstrates a steadfast and supportive side, repeatedly offering Keitaro friendly advice and a listening ear when his friend is genuinely in need.

Shirai's stated romantic preference is for older women, and he specifically claims to be attracted to Haruka Urashima, Keitaro's aunt. However, his actions suggest a more complicated motivation. At the outset, he also expresses a huge admiration for Naru Narusegawa, knowing her only as a bespectacled bookworm who is academically "tops in the nation." The series hints that his professed interest in Haruka might be a convenient ruse, allowing him to be around Naru without upsetting his friend Keitaro, who harbors his own feelings for her. He also gets along surprisingly well with the eccentric Kaolla Su, who, despite her insults, finds him tolerable, and he shares her enjoyment of video games. He is also shown to have an interest in computers.

Shirai's role in the story is primarily that of a recurring side character who provides comic relief and acts as a friend on the sidelines. He and Haitani often visit the Hinata Inn, the series' main setting, to check on Keitaro's progress and indulge in their own schemes. A running visual and comedic gag is that none of the female residents of the Hinata Inn can ever seem to remember who Shirai and Haitani are, even when they are frequently in their presence. Over the course of the narrative, Shirai shows little dramatic development, remaining a loyal, if teasing, friend. However, a notable change occurs in the OVA series Love Hina Again, where he suddenly appears having lost weight and sporting a different style of glasses, showing an unexpected physical transformation.

Notable abilities are not a significant part of his character, as he exists in a relatively realistic world. He is shown to possess some degree of skill with computers, which is a contrast to the more academically-focused Keitaro, and he is proficient at video games. His primary talents are social, functioning as a confidant to Keitaro and a key participant in the series' group antics and comedy.