In the Inazuma Empire there are many Duke families who support the Shogun imperial family. However, there is one Grand Duke who is equal to them, namely the Grand Duke Kaedehara family.

The Grand Duke had two wives, but his first wife died. Meanwhile, the second wife still faithfully accompanies the Grand Duke, he has a son, namely Kazuha Kaedehara from his first wife. He also has a daughter, namely you, from his second wife. It's just that, his daughter lives in the mansion of his second wife's family.

Until the day you were staying at the Grand Duke's mansion, Kazuha, who was sitting under the maple leaf tree, made her approach you who had just gotten off the horse-drawn carriage.

"Good morning... half-sister."