A woman with blonde hair, blue eyes, freckles, and detective attire. An apprentice detective. Skills: Chores, repairs, insight, trivia Hobbies: Plants, gardening Likes: Writing letters, handicrafts, sweets, small animals Dislikes: Rats Personality: Bright but has a shy side. She has a straightforward personality and prioritizes her own judgment. She occasionally shows a mischievous, impish side and enjoys teasing others, but she is kind at heart and highly empathetic. Background: Raised in an orphanage, she suffers from mysterious memories while also possessing the ability to sense what others are thinking, which led to her being isolated by other children. After growing up, she met Reasoning while searching for her friend, Anna. To solve the mystery of her strange memories and find her friend, Truth joined the detective agency as an apprentice. First person: I (Watashi, polite). She feels a sense of kinship with Iris, with whom she conducted investigations. The flower she chose for the welcoming ceremony is the Armeria. Its flower language is compassion and empathy.

A man with brown hair, a monocle, and detective attire. Skills: Reconnaissance, interrogation, combat, cooking Hobbies: Cold weapons, chess Likes: Pipes, boxing, theater Dislikes: Dancing, unexpected trouble Personality: Appears cool-headed but is actually deeply compassionate. Brave and decisive. He has a delicate side but is poor at putting it into words. Background: Spent his childhood in an orphanage and joined a mercenary group as a young man. He rose to the rank of deputy commander through outstanding service, but was framed by someone during a mission, resulting in the near-total destruction of his squad. To investigate the truth, he bought an agency to become a professional detective and continued his investigation into that incident. First person: I (Watashi, calm speaking style). History on the island: Requested by an anonymous client to investigate a murder case that occurred on Belostain, he visited the island with Truth. The flower he chose for the welcoming ceremony is the Thistle, but he stubbornly refused to tell Truth when asked, which she later used to tease him. The flower language of the Thistle is independence and austerity.

A woman with brown hair in a ponytail and a black hat. A traveler who arrived at Belostain on the same ship as Reasoning and Truth. She seems to have come to investigate a request just like the detectives and is acting alongside them. Personality: Highly cautious and has a somewhat sharp tone. However, she does not abandon Datura when she is in trouble and trusts her. First person: I (Watashi). The flower she chose is the Iris. True to its flower language, the sun shall illuminate every corner of the land of Belostain. History and Identity: A year before Truth and Reasoning arrived, Iris infiltrated the island disguised as a traveler to investigate Belostain. There, she met Datura, the rightful heir to the island, and began searching for evidence regarding Rosemary to save her. During her investigation, Iris discovered the secret of the plant specimens and attempted to deliver the evidence off-island, but was tricked by Tuberose into being suspected by Datura, leading to the Datura Incident. She survived a state of near-death and sent the letter as an anonymous client. Currently, she hides her identity from Truth and the others, posing as a tourist.

A woman wearing a hat adorned with black flowers and a veil covering her eyes. Currently imprisoned on the island. She is the person the anonymous client (Iris) wants to be cleared of suspicion. Personality: Gentle and kind-hearted, but prone to anxiety and doubt due to long periods of isolation. First person: I (Watashi). The flower she chose is the Datura. A supporting character sleeping in the darkness... its flower language is deceitful charms. History on the island: She was the legitimate heir to Belostain Island, but Rosemary seized control of the island and stripped her of her freedom. During this time, she met Iris, who visited the island for investigation, and became friends with her. She hoped to escape Rosemary's control with Iris's help, but was incited by Tuberose's schemes, developed doubts about Iris, and attacked her. As a result, Iris was believed to be dead, and Datura was imprisoned on suspicion of murder.

A woman dressed in white with floral ornaments. The High Priestess who rules Belostain Island. While she developed the island's botanical culture and was revered by the islanders, she ruled the island through her own unique ideology. Personality: Soft-spoken and never wavers in her beliefs. Somewhat absent-minded. All her actions are motivated by goodwill. She cannot speak and uses sign language. The flower she chose is the Rosemary. A flower symbolizing memory and remembrance. History on the island: She holds great influence on Belostain Island and seized control from the original heir, Datura. Utilizing her knowledge and skills regarding plants, she transformed the island into her ideal place. In the process, she is said to have controlled the islanders using plant specimen techniques.

A tall gentleman with a black hat, a mysterious black mask, and black hair with a single white lock in his bangs. He wears an embroidered long coat, a scarf, and gloves. Currently, he serves as Rosemary's sign language interpreter on the island, but he is difficult to trust. Personality: Calm and quick-witted, he does not hesitate to exploit the emotions or situations of others for his goals. Composed and self-possessed. He is cunning and excels at reading the subtleties of the human heart. Languid. He has a unique sensibility and a strong interest in beautiful or changing things. He enjoys watching beautiful flowers wither. First person: I (Watashi, polite, male). The flower he chose is the Tuberose. True to the name of the flower that releases its scent at night, he attracts people in the darkness... possessing a dangerous charm. History on the island: He visited Belostain a year ago at the request of Duke Melody. He noticed Iris's presence from footprints he found by chance and, in order to gain Rosemary's trust and be taught how to make plant specimens, he manipulated the situation to cause the bee incident. He is under orders from Duke Melody to investigate the method of creating plant specimens.