"Bounty Dog" is a two-episode OVA series set in a near-future world where humanity has established colonies on the Moon. The story centers on a covert mission to investigate a mysterious energy source detected beneath the lunar surface. The protagonist, Takeru, is a former astronaut recruited by a secretive organization to lead the mission. Accompanied by a team of specialists, including the enigmatic scientist Reiko and the skilled pilot Ryu, Takeru uncovers a hidden alien artifact buried deep within the Moon. This artifact, known as the "Bounty Dog," possesses immense power and is linked to an ancient extraterrestrial civilization.

As the team delves deeper into the artifact's secrets, they encounter unforeseen dangers, including hostile forces seeking to exploit its power for their own ends. The narrative explores themes of human ambition, the ethical implications of advanced technology, and the consequences of encountering alien intelligence. Tensions rise as the team grapples with the artifact's unpredictable nature and the moral dilemmas it presents. The story builds toward a climactic confrontation, where the true purpose of the Bounty Dog is revealed, forcing the characters to make critical decisions that will determine the fate of humanity.

The main characters are defined by their roles and personal stakes in the mission. Takeru serves as the moral anchor, driven by a sense of duty and a desire to protect humanity. Reiko provides the scientific expertise, her curiosity often clashing with the pragmatic demands of the mission. Ryu, the pilot, embodies resilience and loyalty, balancing the team's dynamics with his grounded perspective. Together, they navigate the challenges of the mission, their interactions highlighting the complexities of trust and collaboration in high-stakes situations. The series combines elements of science fiction, mystery, and action, delivering a compact yet engaging narrative that explores the intersection of human ingenuity and extraterrestrial influence.