Today is the release of the 3rd volume for the A Certain Magical Index: Genesis Testament. Even being just released today. The book is now currently sitting on the top 2 Best Selling Light novels by Dengeki Bunko in Amazon Japan.
While the light novel is currently sitting on the Top 20 best selling book in all of Amazon Japan. As a light novel sitting on the Bestselling books in Japan. It is the only Light novel that is in the Top 20 right now!
A Certain Magical Index: Genesis Testaments is the third sequel to the Toaru Majutsu light novels.
Source: Amazon Japan