"Blue Exorcist: Kuro Runs Away From Home" is a short OVA that serves as a side story to the main "Blue Exorcist" series. The narrative centers on Kuro, a familiar and loyal companion to Rin Okumura, who temporarily leaves the True Cross Academy after feeling neglected and unappreciated. Kuro’s departure is triggered by a series of misunderstandings and perceived slights, particularly when Rin and his friends seem to prioritize other tasks over spending time with him. Feeling unwanted, Kuro decides to venture out on his own, seeking a place where he feels valued.

As Kuro explores the human world, he encounters various challenges and humorous situations, highlighting his naivety and curiosity about human life. Meanwhile, Rin and his friends, including Yukio, Shiemi, and Ryuji, notice Kuro’s absence and begin to worry. The group embarks on a search to find him, reflecting on their bond with Kuro and realizing how much he means to them. The story balances lighthearted moments with themes of loyalty, friendship, and the importance of communication.

The OVA maintains the core dynamics of the "Blue Exorcist" universe, with Rin’s fiery determination and Kuro’s mischievous yet endearing personality driving the narrative. The plot is self-contained, offering a brief but engaging exploration of Kuro’s character and his relationship with the main cast. While it does not significantly advance the overarching storyline of the series, it provides a charming and heartfelt addition to the franchise, emphasizing the emotional connections between the characters.