The night of Yona's 16th birthday, the fox-masked person appeared. She aided Yona and Hak to escape from Hiryuu Castle. Little did they know, that the fox-masked person is actually a girl. On top of that, she is actually Himura Erika, their childhood friend! They only know her as the greengrocer in the capital. So, how on earth did she end up getting herself skilled with such swordsmanship? And, why is it that King Il's most trusted person is no other than her? Just who is this Himura Erika? ................. What is she going to do, now that their friendship had come to an end? Whose side she would choose to be with? A sweet and heart-warming story of friendship that will surely catch your heart!