The November issue of Kodansha's Monthly Shonen Sirius magazine revealed on Wednesday that Fuse and artist Mitz Vah's That Time I Got Reincarnated as a Slime ( Tensei Shitara Slime Datta Ken or Regarding Reincarnated to Slime) light novel series will get a spinoff manga series titled Tensei Shitara Shachiku Datta Ken (That Time I Got Reincarnated as a Corporate Slave). Shizuku Akechi is drawing the manga that centers on Rimuru, who re-awakens to the real world in a salaryman job similar to his previous life as Mikami, but still in his slime body.

The manga launched on Wednesday on the "Suiyōbi no Sirius" web magazine, and will serialize there on the second and fourth Wednesdays of the month. The manga will also serialize in print in Monthly Shonen Sirius starting in the magazine's December issue on October 26.

Yen Press licensed the original novel series, and it describes the story:

Lonely thirty-seven-year-old Satoru Mikami is stuck in a dead-end job, unhappy with his mundane life, but after dying at the hands of a robber, he awakens to a fresh start in a fantasy realm...as a slime monster! As he acclimates to his goopy new existence, his exploits with the other monsters set off a chain of events that will change his new world forever!

Fuse launched the story serially on the "Shōsetsuka ni Narō" (Let's Become Novelists) website from 2013 to 2016, and the series has since garnered over 400 million page views. Micro Magazine began publishing the series in print in 2014. The 12th volume shipped on March 9, and the 13th volume will ship on Friday. The series has 4.5 million copies in print.

Taiki Kawakami launched the manga adaptation in Kodansha's Monthly Shonen Sirius magazine in 2015. Kodansha published the eighth volume on June 8, and the ninth volume will ship on Friday. Kodansha Comics publishes the manga in English. The novels also inspired a separate manga spinoff titled Tensei Shitara Slime Datta Ken - Mamono no Arukikata (That Time I Got Reincarnated as a Slime - How Monsters Walk) by Shō Okagiri, which serializes in Micro Magazine's Comic Ride manga website. Micro Magazine published the manga's third volume on March 9, and will ship the fourth volume on Friday.

Yen Press published the novel series' third English volume on August 21, and Kodansha Comics published the seventh volume of Kawakami's manga on August 21.

The novels are inspiring an upcoming television anime that will premiere on October 1. Crunchyroll will stream the series, and Funimation Entertainment will stream an English dub.

Source: Monthly Shonen Sirius November issue and website