"Kisaku Spirit - The Letch Lives" is a supernatural comedy anime centered around the life of Kisaku Seno, a middle-aged man whose lecherous behavior leads to his untimely death. After perishing in a car accident, Kisaku's spirit refuses to move on to the afterlife, instead lingering in the mortal world as a ghost. His newfound spectral form grants him the ability to possess living beings, a power he exploits to continue indulging in his voyeuristic tendencies and pursue his obsession with women.

The narrative unfolds as Kisaku navigates the challenges of his ghostly existence, often clashing with other spirits, exorcists, and supernatural entities. Despite his morally questionable actions, Kisaku occasionally uses his abilities to help others, particularly women in distress, which adds a layer of complexity to his character. His interactions with the living and the dead create a mix of comedic and dramatic situations, blending slapstick humor with moments of introspection.

Key characters include Kisaku's estranged wife, who becomes entangled in his ghostly antics, and a young exorcist tasked with dealing with troublesome spirits like Kisaku. The exorcist serves as both an antagonist and a reluctant ally, often finding herself at odds with Kisaku's unpredictable behavior. Other supporting characters include various spirits and humans whose lives intersect with Kisaku's, contributing to the series' episodic structure.

The plot explores themes of redemption, morality, and the consequences of one's actions, albeit through a comedic lens. Kisaku's journey as a ghost forces him to confront the repercussions of his past behavior, even as he continues to struggle with his base desires. The series balances its humorous tone with occasional moments of emotional depth, creating a narrative that is both entertaining and thought-provoking.