"Engage Planet Kiss Dum" is a science fiction anime series set in a dystopian future where humanity faces extinction due to the emergence of mysterious, hostile entities known as the Shadou. These creatures, which appear as grotesque, biomechanical beings, threaten to overrun the planet. The story centers on the efforts of the Organization, a global defense force, to combat the Shadou using advanced technology and specialized combat units.

The protagonist, Shuu Aiba, is a young pilot who becomes involved in the conflict after a tragic encounter with the Shadou. He joins the Organization and is assigned to pilot the Engage, a powerful mecha designed to combat the Shadou. Shuu's journey is marked by his struggle to understand the true nature of the Shadou and his own role in the war. Alongside him is Ayako Kujou, a skilled and determined pilot who becomes a key ally. Their relationship evolves as they face the horrors of the battlefield and uncover secrets about the Shadou's origins.

The narrative delves into themes of survival, sacrifice, and the blurred line between humanity and technology. As the war progresses, it is revealed that the Shadou are not merely mindless invaders but are connected to a deeper, more complex mystery involving human experimentation and the potential collapse of reality itself. The Organization's leadership, including the enigmatic Commander Kyouko Kagari, harbors hidden agendas, further complicating the conflict.

The series explores the psychological toll of war on its characters, particularly Shuu, who grapples with loss, guilt, and the moral ambiguity of his actions. The plot intensifies as the Shadou's attacks grow more frequent and devastating, leading to a climactic confrontation that challenges the characters' understanding of their world and their place within it. "Engage Planet Kiss Dum" combines mecha action with existential themes, creating a narrative that is both intense and thought-provoking.