The stage is the late 19th century. The Kingdom of Albion was divided due to the Republican Revolution. The capital city of London is divided by a huge wall. The east side is ruled by the Kingdom and the west side is ruled by the Republic. It has become the front line of the Shadow War where spies from various countries are active. Ten years after the revolution, five girls disguised as high school girls appeared at Mayfair Queen's School, a prestigious school in the kingdom, and acted as spies for the Republic. After preventing the Queen's assassination attempt and recuperating in Casablanca, they received new instructions from Control. Taking this mission as an opportunity, the five girls - Team Bai Ge - began to be involved in the huge whirlpool that shook the country.
Control — the Commonwealth's covert ops group — suspects a double agent within the Kingdom's royal family and dispatches Ange and the rest of "Team White Pigeon" to discover the truth.
After an attempt on King Richard’s life, assassins target Princess Mary, the next in line to the throne. Team White Pigeon must protect her while locating deadly Cavorite bombs — a tough feat when Ange is Princess Mary’s sister in disguise.
While the funeral of the assassinated Prince Edward, who was the first in line to succeed the throne, is being held, the nobles of the Kingdom of Albion discuss topics such as whether the second-in-line Princess Mary or the third-in-line Duke of Arkham, Prince Richard, will succeed the throne, and how the Duke of Normandy will act.
