She usually has a smile on her face in many situations, showing her confidence and knowledge. She is also very affectionate towards her people as she told Sora to take care of the Werebeasts if she would lose the coin toss. She, like many other races, used to look down on Imanity. However, she begins to respect them after the alliance, particularly Sora and Shiro. Her respect for Sora increases when she sees his determination and intent on saving Ino and winning the game by another method with no casualties, while she herself believed sacrificing Ino was the best and most efficient solution.
She has long golden hair, fox ears, whiskers, and two golden tails. She typically wears a kimono and a monocle. She also has a giant bell on her chest. Sora had hypothesized Miko's age to be at least 58 years old, but her true age remains unknown. Despite her true age, Miko holds the appearance of a woman in her 20's.
Miko had to spend at least 50 years to unite the various Werebeast tribes into what is currently the Eastern Union, in which she lost her original name in a bet and gained her title as she contacted with a certain Old Deus. As the leader of the Werebeasts, she was responsible for the expansion of the Eastern Union and thus played games against the Imanity (8 times), the Elves (4 times), and the Flügel (1 time), although it is unknown whether she played the games herself or sent a representative in her stead. The Werebeasts were once known for never challenging other races in games, but always being victorious when challenged.
Later, after the siblings had won over all the lands the Werebeast claimed on the continent, Miko challenges them to a game match, which was decided as a coin flip. Circumstances made a tie favorable to simply winning the coin flip, and thus the Eastern Union formed an alliance under Elchea and named it the Elchea Federation.
As of Light Novel Volume 7, she bets her life as part of the bet in the dice game against the Old Deus.