Bluesy Fluesy, often referred to by the nickname Izzy, is a central figure and the second protagonist of the story. She is a silver-haired girl of small stature, standing 151 centimeters tall, who appears to be a teenager but is actually older than she looks due to a unique circumstance. Her youthful appearance is a direct result of her possessing a powerful tattoo, or spell, which has halted her physical aging as a kind of price for its use. This stunted growth is considered a special case among those who wield such powers. She is a former lieutenant in the United States Army and operates as an agent for a unit known as Team Bluemoon, which is tasked with investigating and collecting these supernatural tattoos.

In terms of personality, Izzy presents a complex mix of traits. She is highly skilled, confident, and possesses a professional demeanor befitting her military background. However, she is not without a lighter, more mischievous side. She has been known to make deliberately provocative statements, such as falsely implying a romantic relationship with the main protagonist, Seigi, seemingly for her own amusement and to disrupt the status quo. Despite this playful streak, she is deeply caring and loyal, particularly towards her friends and allies, and carries a locket with a picture of someone important to her, suggesting a sentimental nature. Her initial motivation is to serve her country and manage the growing threat posed by rogue tattoo users, but she is also driven by a personal desire to protect others from the potential abuses of these powers, a conviction that sometimes puts her at odds with her own government's agenda.

Izzy's role in the story begins when she encounters Seigi, a martial artist who recently acquired a tattoo of his own. After an initial confrontation where she tests his abilities, she recognizes his unique potential and recruits him to work alongside her, aiming to help him control his dangerous power. Her primary role is that of a mentor and a battle-hardened ally, guiding Seigi through the complexities of the secret war being fought over the tattoos. Her key relationships are central to her character development. She is frequently accompanied by her faithful partner, Tom, who provides support and counsel. Another profound relationship is with a character known as BB, a former major in the US Army and her former lover, whose past decisions greatly impact her actions and emotional state. Her dedication to her friends, including a girl named Lisa, often puts her in direct conflict with powerful enemies.

Throughout the narrative, Izzy undergoes significant development. She is initially a dutiful soldier, but as she witnesses the morally ambiguous objectives of the US military, including potential plans for world domination using the tattoos, she becomes more disillusioned. This internal conflict forces her to question her loyalties. Her development is marked by a severe physical cost as well; after a grievous injury in battle, she loses the arm that bore her tattoo, an event that frees her from the burden of her power but also leaves her permanently scarred. Ultimately, she chooses to leave the military and follow her own moral compass, allying with Seigi and others to uncover the deeper truths behind the tattoos and prevent a larger catastrophe.

As for her notable abilities, even without using her tattoo, Bluesy Fluesy possesses extraordinary physical prowess that allows her to easily overwhelm opponents, including Seigi. Her combat skills are sharp and refined from years of experience. Her spell is activated by using chalk as a trigger, allowing her to compress air. This compressed air can be deployed as a bomb for offensive attacks or wrapped around her body as a cushion to absorb shocks and protect her from damage.