When the enigmatic Sirens emerge from the depths of the sea, humanity's trajectory takes a sharp turn. In response, the military coalition known as 'Azur Lane' is formed to combat this newfound threat. Despite temporarily halting the Sirens' advance, tensions brew within the alliance, sparking internal strife. Amidst this turmoil, a tranquil military harbor stands as a sanctuary from the chaos of war. Here resides Belfast, a striking silver-haired maiden and the esteemed chief maid of the Royal faction. As the second vessel of the illustrious Edinburgh class, the Royal Navy's premier cruiser, Belfast navigates a whimsical daily routine fraught with unexpected twists and turns.