Mio Tsukushi is a teleporting esper within the organization P.A.N.D.R.A., identifiable by her blonde hair styled in a spiky ponytail with left-side bangs and brown eyes.

She holds strong admiration for Kyousuke Hyoubu, seeing him as her savior, and exhibits jealousy toward Kaoru Akashi due to Hyoubu's perceived favoritism. This jealousy stems from deeper insecurities rooted in feelings of neglect from her parents and a lack of security within P.A.N.D.R.A. Her emotional vulnerability and self-neglect surface dramatically during an incident involving an out-of-control clone. Kaoru protects Mio during this conflict, leading to a shift in their relationship. Though rivalry persists, Mio gradually becomes more peaceful and cooperative, partly influenced by Hyoubu increasing his attention toward her after the clone event.

Her teleportation operates through portals, not instantaneous bodily movement. She manipulates these portals to move individual body parts, grab others' limbs, or pull them through. A notable application involves generating clones by creating cellular portals that maintain divided bodies as a single entity. However, overusing this cloning power risks the clones gaining independence and turning hostile; one rogue clone merged with machinery to form a destructive entity.

Later within P.A.N.D.R.A., Mio takes on responsibilities like locating Kaoru, leveraging her position as Kaoru's sole friend in the organization. Her interactions with Kaoru reveal a tsundere aspect, repeatedly denying her growing respect and loyalty despite evident behavioral changes.

Her name originates from the chapter "Miotsukushi" in *The Tale of Genji*. The surname Tsukushi combines "筑" (an ancient musical instrument) and "紫" (purple), while the given name Mio (澪) means "water route" or "shipping channel".

Mio evolves from a jealous, insecure individual into a more stable and active P.A.N.D.R.A. member, demonstrating increased cooperation and reliability, especially on missions involving her former rival.