Based on the light novel written by Carlo Zen, illustrated by so-bin, and published by Hayawaka Publishing. Two volumes have been published since 2017 and it considered still being published.
Based on the Japanese science fiction novel Yakitori by Carlo Zen and published by Hayakawa Publishing Corporation.
"Yakitori" is a dish of bits of boneless chicken, usually marinated, skewered, and grilled. The mercenaries are called thus because they face a huge 70% casualty rate during combat duty, and "grilling" is even the slang for serving planet-side duty.