S'more Milwalky is a genius scientist assigned to the morgue of Deslike Prison, also known as Dead End Prison. Her expertise lies in embalming—restoring damaged corpses to near-perfect condition—and she spends her days performing this meticulous work with no time for romance. One day, the body of Painkiller, a notorious mass murderer executed for his crimes, is brought to her lab. Captivated by his handsome features, S'more inadvertently uses her entire supply of a secret elixir during the embalming process, which causes Painkiller to come back to life. Rather than report the anomaly, she declares him her husband and takes him home.

Painkiller, now renamed Dead Painkiller, finds himself caught in a surreal new existence. S'more has sewn threads and bone-conduction devices into his body, giving her control over his movements and the ability to dismantle him if he disobeys. He is a hardened killer who has known only violence and isolation, but S'more's obsessive, carefree, and dangerously affectionate behavior forces him to confront a kind of intimacy he never expected. The series follows their twisted domestic life, with Painkiller reluctantly playing the straight man to S'more's increasingly unhinged antics.

The setting expands as the story progresses. The prison warden, a sadistic figure, becomes a primary antagonist. He is fixated on creating the perfect convict—someone he can kill repeatedly and revive—and sees Painkiller as the ideal subject. This threat forces S'more and Painkiller to work together, and Painkiller slowly starts to consider whether he wants to live by his own choice rather than merely being S'more's puppet. Additional characters include S'more's eccentric parents—a mother who practices black magic and a father who is a doctor and anatomist—as well as a recurring gag involving a character named Ono who suffers repeated dismemberment and decapitation.

The narrative is divided into seventeen chapters collected in two volumes. The first volume establishes the bizarre cohabitation and introduces the prison setting and Painkiller's reluctant adjustment. The second volume escalates the conflict with the warden, pushes Painkiller toward a decision about his own agency, and culminates in his acceptance of a new life alongside S'more. The tone balances dark comedy, gore played for laughs, and a genuinely affectionate if twisted bond between the leads. The manga concludes with Painkiller choosing to live on his own terms, embracing a relationship that is as dangerous as it is loving.