In the manga's story, cells work in a "black" environment in the body of a human in poor health. The person drinks and eats too much, has insufficient physical activity, and has high stress.

A witch has stayed single for 300 years. Is this finally her lucky break?

Once, Kurokawa Mikage was the fearful “Witch of Moonlight,” but now, 300 years later, she’s just an office lady and teased by her co-workers for still being single. Mikage thinks she’s fine with her ultimate spinster life, posting fake photos of a pretend relationship… Until the young and handsome Kobayashi Satoru joins her company! Is this the start of a real, bewitching romance at last!?