The manga is a verified, official adaptation of Tokuya Higashigawa’s mystery novel series. It was published by Shogakukan, illustrated by Ayame Kojima, and serialized in Monthly Flowers from 2011 to 2013. It remains a faithful yet visually distinct retelling of the first few cases, and is recommended for fans of the original novels or the drama who want a closer, illustrated version of Kageyama’s deductions.
The term “verified” in this context typically refers to —not a fan theory. Here is the factual confirmation: