Keigo is typically a goofy and an extremely hyper-active character, often using overly-dramatic movements and words to act out his feelings. In other respects, he is the stereotypical Japanese teenager: he enjoys watching fireworks, playing role-playing-games, going to beach parties, and so forth. Originally little more than a source of comic relief, Keigo becomes a more prominent character later in the series. The Asano family consists of Keigo's mother, father, his sister Mizuho, and Keigo himself. Like Tatsuki Arisawa, he is unusual in that he lives with both of his parents, unlike many other recurring characters in the series.

A good-natured teenager, Keigo is used mainly for comical effect, usually in situations involving failed attempts to woo girls and interacting with Ichigo. He is good friends with fellow student Mizuiro Kōjima, whose calm, innocent demeanor, and success with women acts as a foil to Keigo's impulsive, wannabe personality.

Keigo appears to be a shallow character at first glance, with a passion for slacking off. Indeed, he takes great pride in not making it to the honors roster (higher than the 50th ranking) and labels those who do so "traitors" (including Ichigo and Chad, who made the 23rd and 11th ranks respectively). However, Mizuiro states that Keigo is much smarter than his bad grades show.

Later, it is revealed that Keigo can see ghosts and even soul reapers, in the Hueco Mundo/Arrancar arc. The first soul reaper Keigo ever saw was Ikkaku Madarame, who saved him from an arrancar. Keigo also got to see Ichigo in soul reaper form, before Ichigo left for Hueco Mundo at Urahara's underground training site, with Tatsuki and Mizuiro.

(Source: Wikipedia)