To be reincarnated into another world with the promise of a “cheat” power is one thing… but to be reborn as a baby, and then left for dead after your royal parents think you’re powerless?? That’s another thing entirely! Now the newly-born Reinhart—or Hart to his new friends—must find his way through a dangerous world…but luckily he’s got magic that’s quite literally off the charts!
Takahashi launched the manga in the Kodansha‘s Suiyōbi no Sirius section of the Nico Nico Seiga website in April 2019. Kodansha published the manga’s sixth compiled book volume in November 2021. Kodansha Comics published the fifth volume digitally in September 2021.
Sumimori began serializing the story in the Shōsetsuka ni Narō website in September 2018, where it is still ongoing. Kodansha published the first print novel volume with illustrations also by Ai Takahashi in May 2019, and it published the fifth novel volume in October 2021.
Source: Nico Nico Seiga‘s Suiyōbi no Sirius section