Why does the Spy x Family anime look different from the manga?

Two different hands are responsible. The manga is drawn by Tatsuya Endo alone: ink, screentone and his famously clean line, the quality editor Shihei Lin singled out when the series launched. The anime's characters were redesigned for movement by Kazuaki Shimada, the character designer of The Promised Neverland, who rebuilt Endo's drawings as model sheets that hundreds of animators at two studios could hold consistent. Endo supervised the translation personally: in interview he has described checking the design drawings Shimada sent him as they arrived.

The production structure is the other half of the difference. The anime, announced on November 1, 2021 and premiered on April 9, 2022, is a genuine co-production between Wit Studio and CloverWorks, an arrangement Japanese television anime rarely attempts, directed in its first season by Kazuhiro Furuhashi with music by (K)NoW_NAME. Shimada's key visuals announced the design philosophy at once: he drew the cast in two registers, a severe mission mode and a warm family mode, and the series has cut between those two faces ever since.

Personnel shifted while the designs held. Season 2 (October to December 2023) kept the core staff, with Ichiro Okouchi taking over series composition; season 3 (October to December 2025) was directed by Yukiko Imai. The paper trail of the translation survives as an object: the Spy x Family Animation Art Book, released by Wit Studio on December 8, 2023, prints 200 pages and roughly 300 pieces of setting material, the model sheets, props and backgrounds where Endo's manga becomes Shimada's anime.