; : :Lag Seeing is a determined 12-year-old boy born on the Day of Flicker. He wields the Shindanjuu, a specialized gun that fires "Akabari" (Red Needles) using fragments of the heart. His left eye, made of red Spirit Amber, enhances his marksmanship and allows him to project heart bullets. This same ability lets him visualize the memories of objects. In his childhood, his mother was taken by men from Akatsuki, the capital of AmberGround, and an encounter with the Letter Bee Gauche Suede inspired him to follow the same path. He initially carries an antique revolver but later inherits Gauche's Nocturne #20. During a critical moment, Lag awakens a new power, his body glowing like Spirit Amber as he fires a special bullet in an attempt to restore Noir's heart. His companion, Niche, joins him after he saves her from a Gaichuu and she glimpses his memories through the Shindanjuu. ; : :Niche is Lag's Dingo, traveling with her pet Steak. She wields her "Golden Sword" hair as razor-sharp blades and has bear-like claws. Found as an undeliverable letter at a train station, Lag names her Niche after rescuing her from disposal. Though delivered to "Lovesome Downs", she escapes captivity as "The Child of Maka"—a legendary figure from the north. After Lag saves her from Gaichuu territory, she becomes his Dingo. Believed to be seven, she's actually 200 years old, born in Blue Notes Blues. She later discovers she has a twin sister and is truly Maka's offspring. ; / : :Gauche Suede is a Letter Bee who once rescued Lag when he was marked as a letter in Yodaka District, delivering him to his aunt in Campbell. Driven by his desire to become Head Bee and provide for his sister Sylvette, he later reappears as the emotionless Marauder Noir, having lost his memories. As Noir, he ruthlessly steals letters yet remains fiercely protective of Roda. On the Day of Flicker, Gauche lost his mother in childbirth, leaving him devoted to Sylvette's happiness. Lag's attempt to restore his memories with a letter bullet only partially succeeds, transferring Lag's memories of him instead. Gauche's combat abilities include the Kurobari (Black Needle) attack. Once wielding Nocturne #20 as a Letter Bee, he now carries the Gymnopédie, capable of the Raven Black technique. ; : :Gauche's younger, paraplegic sister, who was born on the Day of Flicker. After he left to go to Akatsuki, he later disappeared and she believed him to be dead, but later learns that he is alive. By the end of the story, the sun takes her heart, but Lag reclaims it. ; :Gauche's Dingo. She is a dog who specializes in fighting and tracking and is a skilled hunter. ; : :A child who Reverse's leader gave to Gauche as an assistant and whom he subconsciously named after his former Dingo. She was a failed experiment, having been mixed with several species/creatures, but was abandoned after the experiment failed until Lawrence found her. ; : :Steak's pet, who began accompanying her after she destroyed Love Someone Down's sideshow and has the ability to sniff out a Gaichuu's weak spots. He is implied to be the last of the
Kapellmeister, a species that once coexisted with the Spirit Insects and is now thought to be extinct. ; : :Connor is a veteran Letter Bee who guides Lag to his interview and frequently delivered mail to Campbell during Lag's childhood. He falls for Sunny, a girl from Lamento Town's abbey, unaware she belongs to the rebel group Reverse. When the abbey's residents lose their hearts to the Cabernet Gaichuu, Connor attempts to fight it in despair before collapsing. He stays by Sunny's side as she lies comatose, refusing to give up hope. She eventually recovers when it's discovered part of her heart remained, later becoming his girlfriend. Connor's Spirit Amber technique, "Heart Landmine", involves planting explosive shards of his "Appetite" that detonate on contact. ; : :The master of the Bee Hive, who later joins Reverse, having been as a test subject by them, and plans to overthrow the government. ; : :The sub master of the Bee Hive, who acts as Largo's right-hand man. Aria's Spirit Amber ability is the Heart Restoration Bullet, which she executes by playing music on her violin. It has a healing effect on those who hear it, which is stronger on those closer to her. Her Spirit Amber attack is "Benihiiro no Senritsu" (Crimson Melody), which is emitted from her violin. ; :Lag's aunt, who lives in Campbell Litus and whom Gauche entrusted with Lag's care. She is a good friend of his mother, the current Empress. ;Dr. Thunderland Jr. : :A biologist who works for the Third Bioscience advisory panel of AmberGround division. He specializes in
pathology and collects corpses for dissection and study, earning him the nickname "The Corpse Doctor". Despite his job, he has a kind heart, as he makes a star-shaped memorial for each corpse he dissects. Zazie once hated him because he thought he had taken a group of street kittens, but in reality he had quarantined them because of a disease. He is also one of the five survivors of the airship that crashed on the Day of Flicker. ; : :A Letter Bee. When he was a child, his parents were killed by a Gaichuu, leading him to become a Letter Bee in order to seek revenge against the Gaichuu, whom he is skilled at killing. Since he has dedicated himself to killing Gaichuu, he does not care for delivering letters. Zazie is fond of cats, which caused him to hate Dr. Thunderland because he thought that he had killed an alley cat he was feeding. However, he forgives him after learning that he had quarantined the cat because of a disease. Zazie is also fond of Jiggy Pepper and looks up to him. Zazie's Spirit Amber attack is Aotoge (Blue Thorn), which uses shards of his "Malice" instead of his heart. ; :Zazie's Dingo, which is a black panther. It has stuck with Zazie since it was a kitten out of fondness towards him. ; : :A Letter Bee who is first mentioned by his adopted sister, Nelli, and who Zazie looks up to. He seeks to become stronger for her, and only follows who he wants to follow. Nelli hated him because she blamed the death of her brother Nello on him leaving them. Jiggy later saves Lag from a giant Gaichuu, telling him that had received a letter from Nelli telling him about his efforts, and thanks him before departing. Largo later entrusts him with caring for Zazie, and they leave to pursue the Gaichuu heading towards Akatsuki. His Dingo is a hawk named Harry. His Spirit Amber is Gunjou, Sea Blue Ultramarine, which he executes through a Shindanjuu he carries besides his motorcycle. ; :Lag's mother, who at the beginning of the story was kidnapped by men from Akatsuki. She is later revealed to be from the royal bloodline and part of the machine keeping the artificial sun lit. During the Day of Flicker, she was struck by a fragment of heart, causing an accelerated pregnancy. After giving birth to Lag, who was a being of pure heart, she had Sabrina place a Spirit Amber in his eye socket to prevent him from fading away, which gave him human form. ; :Reverse's leader, who aims to plunder the letters that Letter Bees deliver. He gave Gauche his new identity as Noir. ==Media==