Who designed the Evangelion characters and mecha?

The character designs are by Yoshiyuki Sadamoto, who made a decision that still defines the series: the children look ordinary. Shinji, Asuka and Rei wear school uniforms and plain clothes, their hair is drawn in naturalistic styles for anime of the period, and Sadamoto has said Rei's design, pale skin, blue hair and red eyes, was built from a few strong accents so she would read instantly at any size. The plugsuits are the exception, tight biomechanical garments that belong to the machines' world rather than the school's.

The Evangelions themselves were led by mechanical designer Ikuto Yamashita, working to Anno's brief for something closer to a restrained demon than a robot: tall, thin, long limbed, with a hunched posture and visible jaw and teeth beneath the helmet. The armour is framed inside the fiction as restraints on a living giant, which is why the designs include an umbilical power cable, an entry plug in the spine, and progressive armour damage that reveals organic tissue.

Supporting design work spread across the Gainax and guest team: Mahiro Maeda contributed concepts including elements of the later Angels and weaponry, and the Angels themselves range from geometric solids to a shadow, a virus and a beam of light, a variety that was itself a design statement against the humanoid monster tradition.

For collectors, design authorship explains the art book market. Sadamoto's illustration books sell the characters, the Groundwork volumes sell Yamashita's and the animators' machines, and original packaging credits distinguish design roles precisely, with character design and mechanical design listed separately on Japanese releases. Reproductions that blur those credits are a quick warning sign of unofficial merchandise.