"Shironeko Project: Zero Chronicle" is a fantasy anime series based on the mobile game "Shironeko Project" (also known as "Rune Story"). The story is set in a world divided into two realms: the Kingdom of Light and the Kingdom of Darkness. These realms are locked in an eternal conflict, with the Kingdom of Light seeking to maintain peace and order, while the Kingdom of Darkness strives to reclaim its lost power and territory. The narrative explores themes of war, destiny, and the blurred lines between good and evil.

The protagonist, a young prince from the Kingdom of Light, embarks on a journey to fulfill his role as the "Chosen One," destined to bring balance to the world. Alongside him is Iris, a loyal and skilled knight who serves as his protector and confidante. The prince's journey is fraught with challenges as he encounters various factions, including the enigmatic Kingdom of Darkness, led by the mysterious and powerful Dark King. The Dark King seeks to harness the ancient power of the "Black Dragon" to overthrow the Kingdom of Light and reshape the world according to his vision.

As the prince travels, he uncovers the truth about the origins of the conflict between the two kingdoms. The story delves into the history of the Black Dragon, a being of immense power that was sealed away to prevent its destructive potential. The prince learns that the Black Dragon's awakening could spell doom for both realms, and he must confront the moral complexities of his mission. The narrative also introduces other key characters, such as the spirited adventurer Fina and the stoic warrior Kite, who each play pivotal roles in the unfolding events.

The series builds toward a climactic confrontation between the prince and the Dark King, as the fate of both kingdoms hangs in the balance. The prince is forced to grapple with the weight of his destiny and the consequences of his choices, as the line between hero and villain becomes increasingly ambiguous. The story concludes with a resolution that ties together the themes of sacrifice, unity, and the cyclical nature of conflict, leaving room for reflection on the broader implications of the characters' actions.