Inu mo Kuwanai

Utsugi is a young investigator employed by a private detective agency, accustomed to the routine nature of his work. His latest assignment takes an unexpected turn when he is hired by Yamashiro, a college professor, to surveil his wife and uncover evidence of infidelity. As Utsugi delves into the case, he quickly confirms that the professor's wife is indeed involved with another man—Okuzono Shuji, a fellow academic at the very same university. However, this discovery reveals far more than a simple affair. Utsugi soon learns that this pattern of betrayal is deeply entrenched in the men's shared history. Okuzono has repeatedly seduced and stolen away the women Yamashiro cared for on countless prior occasions, establishing a long-standing cycle of romantic sabotage between the two academics. What initially appeared to be a straightforward investigation gradually exposes a dark, convoluted web of obsession and rivalry among these intellectuals. Their twisted dynamic defies conventional logic, blurring the lines between victim and aggressor. Now, caught in the gravitational pull of their destructive relationship, the young investigator finds himself unwittingly drawn into a complex psychological entanglement far beyond the scope of his original commission.