The Bleach manga and anime series features an extensive cast of characters: aside from humans and spirits, there are Soul Reapers, Quincies, Hollows, modified souls, Bounts, Arrancars, Vizards, the Xcution, and Zanpakutō Spirits.
Bleach's creative process is focused around character design. When writing plotlines or having difficulties generating new material, Tite Kubo begins by thinking of new characters, often en masse, and rereading previous volumes of Bleach. Kubo has said that he likes creating characters with outward appearances that do not match their true nature, an element that can be found in many Bleach characters, as he is "attracted to people with that seeming contradiction", and finds an "urge to draw people like that when [he] works." When creating characters for the manga, Kubo first designs character appearances and only then decides what their personalities will be, in reflection of what he drew. When brainstorming character designs, he will go out and draw the faces of real people he sees, a hobby of his dating back to childhood. Kubo considers every character to be unique and wants each of them to have the opportunity for character development in the course of the series. When asked about potentially-romantic relationships between certain characters, Kubo states that he "doesn't want to turn the series into a love story", since he thinks there are more exciting aspects of their personalities to draw out.
Kubo has cited influences for elements of Bleach ranging from other manga series to music, foreign language, architecture, and film. He attributes his interest in drawing the supernatural and monsters to Shigeru Mizuki's Ge Ge Ge no Kitaro and Bleach's focus on unique weaponry and battle scenes to Masami Kurumada's Saint Seiya, both manga Kubo enjoyed as a boy.Bleach was first conceived from Kubo's desire to draw a shinigami in a kimono, which formed the basis for the design of the Soul Reapers. Several characteristics from them such as the kidō spells and the zanpakutō swords are also based on Japanese literature.Rukia Kuchiki was the first character Kubo designed, but he did not see her as a lead character, so he created Ichigo Kurosaki to be the series protagonist. Other characters from the series also use different languages to describe their terminology; the powers from the Quincy are taken from German, while Hollows and Arrancar instead use Spanish terms; for the latter, Kubo believed that the language sounded "bewitching" and "mellow" and that felt appropriate for a species of ghost. The names of several Arrancar are based on famous architects and designers who inspired scenery appearing in Bleach.