Miki is Hinamori Amu's second guardian character to awaken. She is somewhat tomboyish in personality and is an artistic type. She can often be seen sketching something in her book.

When Amu does a chara change with Miki, she gains Miki's artistic abilities. When she transforms with Miki, she becomes Amulet Spade and gains the ability "Colorful Canvas."

Miki represents Amu's desire to be more level-headed and artistic. Miki is the one who helps Amu with fashion choices and Amu's love interest.

Miki has shown an interest in Tadase's guardian character, Kiseki, Ikuto's guardian character, Yoru, Kukai's guardian character, Daichi, Kairi's guardian character, Musashi, and Nagihiko's second guardian character, Rhythm. During change, Amu gains increased ablities.On character transformation, Amu is Amulet Spade.