This week’s Japanese book rankings saw a major victory for one of the most beloved isekai franchises. Volume 31 of That Time I Got Reincarnated as a Slime claims the No. 1 spot on Billboard Japan’s Book Hot 100 chart, according to the latest list released on February 19.
The manga adaptation of Tensei Shitara Suraimu Datta Ken, created by Taiki Kawakami and based on the original work by Fuse with illustrations by Mitz Vah, dominated across multiple sales categories. The series once again proves its enduring popularity among readers in Japan.
Understanding the Billboard Japan Book Hot 100
The Billboard Japan Book Hot 100 is not just a simple sales ranking. It is a comprehensive chart that measures overall performance by combining:
Physical bookstore sales
E-book downloads
E-commerce (EC) transactions
Subscription platform data
Library lending figures
Social media engagement
By integrating these diverse metrics, the chart reflects not only commercial success but also cultural buzz and reader engagement across Japan.
Manga Dominate the Top Five
This week’s chart highlights the overwhelming influence of manga titles. The latest installment of That Time I Got Reincarnated as a Slime secured first place by leading both physical bookstore sales and digital downloads, while also ranking strongly in online commerce.
Coming in at No. 2 is Mystery to Iu Nakare (Don’t Call It Mystery) Vol. 16 by Yumi Tamura. The series gained additional recognition following its live-action television adaptation in 2022. This new volume kicks off the highly anticipated “Island Arc,” giving fans a fresh storyline to explore.
Meanwhile, Vol. 23 of Chainsaw Man by Tatsuki Fujimoto continues its strong performance. After debuting at No. 2 last week, it remains in the top tier, showing consistent demand in both physical and digital formats.
Rise of “Naro-kei” Adaptations
Several works adapted from the popular user-generated novel platform Shosetsuka ni Naro also secured positions in the top five. Often referred to collectively as “Naro-kei” titles, these series continue to bridge the gap between web novels and mainstream manga success.
Among them:
Mugen Gacha (Unlimited Gacha) Vol. 21
I Was Reincarnated as the 7th Prince so I Can Take My Time Perfecting My Magical Ability Vol. 22
Both series highlight the continued demand for fantasy and reincarnation-driven narratives in Japan’s publishing market.
A Notable Climber: Ichijigen no Sashiki
Another standout this week is Ichijigen no Sashiki (Labyrinth of Hortensia and the Minotaur) by Ryunosuke Matsushita. The sci-fi mystery novel jumped from No. 15 last week into the top 10 for the first time, landing at No. 8.
The title has performed especially well in social media metrics, maintaining a high ranking for two consecutive weeks. Physical bookstore sales have also shown steady improvement, signaling growing word-of-mouth momentum among readers.
Top 10 Titles (Feb. 9 – Feb. 15 Tracking Period)
Below are the top 10 books on this week’s Billboard Japan Book Hot 100:
Tensei Shitara Suraimu Datta Ken (That Time I Got Reincarnated as a Slime) Vol. 31 – Taiki Kawakami, Fuse, Mitz Vah
Mystery to Iu Nakare (Don’t Call It Mystery) Vol. 16 – Yumi Tamura
Chainsaw Man Vol. 23 – Tatsuki Fujimoto
My Gift Lvl 9999 Unlimited Gacha Vol. 21 (Comic Edition) – Takafumi Omae, Shisui Meikyo, tef
I Was Reincarnated as the 7th Prince so I Can Take My Time Perfecting My Magical Ability Vol. 22 – Yosuke Kokuzawa, Kenkyo na Circle, Meru.
In the Megachurch – Ryo Asai
Welcome to Demon School! Iruma-kun Vol. 47 – Osamu Nishi
Ichijigen no Sashiki (Labyrinth of Hortensia and the Minotaur) – Ryunosuke Matsushita
The Case Files of Kindaichi Papa Vol. 3 – Seimaru Amagi, Fumiya Sato
Blue Box Vol. 24 – Kouji Miura
Slime Continues Its Reign
The continued success of That Time I Got Reincarnated as a Slime underscores how powerful the franchise remains in Japan’s competitive publishing landscape. With strong performance across nearly every measurable metric, the series shows no signs of slowing down.
As manga titles dominate the charts and web-novel adaptations keep rising, the Book Hot 100 once again reflects the dynamic evolution of Japan’s literary and pop culture scene. Fans will be watching closely to see whether the slime-powered phenomenon can maintain its grip on the top spot in the weeks ahead.v