Spy x Family author Tatsuya Endo revealed in the SPY x FAMILY Official Fanbook: EYES ONLY that he has no attachment with the characters of his current work.

In the interview, when Blue Exorcist author Kazuo Kato complimented Endo for the character design of Loid Forger, the author replied, “I gave up on what I originally wanted to draw and drew what the world wants to see, not myself, so I have no attachment to the characters (laughs).”

He revealed that he was told by his editor that “cool” characters like Loid and “cute” characters like Anya are important for manga popularity. However, Endo continued to create works like Ishi ni Usubeni and Tetsu ni Hoshi which ultimately did not become popular in the industry.

In fact, the author also mentioned in a different interview that he doesn’t really like spies. He explained that to him “to have a secret identity” is something exciting and so he chose spies to channel that concept.

In the fanbook, Endo also stated that he started working on Spy x Family to break out of an artist’s block and considers this manga as a “rehabilitation work”.

“Spy x Family is a rehabilitation work for me to revive as a mangaka when I fell into a slump,” said Endo.

However, MangaPlus editor Shihei Lin revealed in “The Making of a Jump Manga!” interview that after finishing TISTA and Gekka Bijin for Jump Square and finishing three one-shots with editor Lin, who Endo had known and worked with for more than 10 years, the two began to plan for a series that would feature in Shōnen Jump+.

This manga would combine what Lin thought were the strengths of Endo’s previous works; Rengoku no Ashe, Ishi ni Usubeni, Tetsu ni Hoshi and ISpy, creating Spy × Family.

Lin claimed that the reception for Spy × Family from their editorial department was so good that its serialization was “practically decided” before an official meeting for it took place.

Spy × Family is a Japanese manga series written and illustrated by Tatsuya Endo. It has been serialized biweekly on Shueisha’s Shōnen Jump+ application and website since March 2019, with the chapters collected in nine tankōbon volumes as of April 2022.

The manga has exceeded over 350 million reads on the Shonen Jump+ digital platform and over 17 million copies of the collected volumes were printed (physically) and sold (digitally) in Japan.

Viz Media has licensed the series for English release in North America.

According to the recent Oricon sales records, Spy x Family became the best-selling series in Japan in April 2022 with most volumes of the same ranking in the volume-wise sales chart. The sales number is mostly boosted by the release of the anime in Spring 2022.

Source: Yaraon(1,2), “The Making of a Jump Manga!” Interview