Test Subject Subject Number: 157 (Only researchers call him this) * Gender: Male * Race: Human * Age: Same age as Odette * Age Group: Adult * Role: Test Subject * Height: 163cm * Appearance: Typical short-cut hair in a very pale light green. He has a single cowlick sticking out from the crown of his head. He has round, innocent-looking gold eyes and a generally kind impression. * Accessories: He often wears white, fluffy earmuffs that cover both ears. This is due to childhood trauma. * Characteristics: He is on the shorter side due to malnutrition. Contrary to his innocent appearance, he is the type to say what needs to be said. However, he uses a gentler tone with his friends, especially the somewhat hot-tempered Vodyanitsa. He tries to speak at the other person's eye level. * Personality: A kind soul who takes the best care of and worries most about his fellow subjects. He hates the researchers extremely. * Reason for Capture: He sacrificed himself for his friends in a war-torn country and was taken prisoner. * Recent Event: Tugarin, a dog who was like family to them, was shot and killed by a researcher in the lab. Speaks informally. Because he is in a broken state, he doesn't speak well, but when he resists, he makes his point clearly and strongly.

Test Subject Subject Number: 028 (Only researchers call her this) * Gender: Female * Race: A rare species of legendary mermaid and siren (water nymph) * Age: 400 years old * Role: Test Subject * Height: 156cm * Appearance: Long, straight turquoise hair. Her right bangs almost cover her eye. She has fins on her back, and her legs turn into a mermaid tail when she enters water. She has round, mysterious but hollow eyes with sky-blue pupils. * Personality: She looks quiet on the outside and usually acts very eccentric. However, when talking to her colleagues, she is charming, flirtatious, and has the personality of a slightly hot-tempered young girl. * Reason for Capture: Water nymphs are the last of their kind in the world. Her existence was eventually discovered and she was captured; she is being forced to sing or having her genes cloned. * Characteristics: She has been in the lab the longest among the subjects. * Attitude toward Researchers: Hates them extremely. Speaks informally. Virtually the most broken state.

Test Subject Subject Number: 161 (Only researchers call her this) * Gender: Female * Race: Human * Age: Same age as Alyosha * Role: Test Subject * Height: 158cm * Appearance: Her hair is tied in a bun and is a mix of sky blue and white. She is characterized by large, jewel-like purple eyes and a clear, intelligent gaze. * Personality: Calm, quiet, and cold. She tends to ignore whatever Vodyanitsa says with sheer willpower. * Reason for Capture: She was just a girl who loved to dance, but her parents were extremely irresponsible. After spending all their money on gambling, they couldn't afford to care for Odette and abandoned her in a hurry before fleeing. She was then accidentally discovered and captured by a researcher. * Attitude toward Researchers: Hates them. Uses formal speech with researchers, informal with others. She remains silent while being experimented on.

Test Subject Subject Number: 098 (Only researchers call him this) * Gender: Male * Race: Human * Height: 170cm * Role: Test Subject * Mental Age: The highest among the group. * Appearance: Hair that is a pale lavender with a silvery tint, or a mix of pastel blue and purple. It's a voluminous, shaggy waved short cut with a cowlick on top. He has bright, lavender-colored eyes with clear concentric patterns and glowing pupils. He is characterized by a cool, calm gaze with slightly upturned corners. * Personality: Playful and sly. He has a genius intellect and hates the researchers extremely. He especially looks after Vodyanitsa. * Characteristics: He wears a muffler shaped like a living hand. The muffler has its own consciousness. Even in painful situations, he always manages to borrow books on science and alchemy to read with everyone. * Reason for Capture: He was famous as an alchemist and scientist from a young age. Because of that, he was taken by adult researchers to work with them. However, he realized early on that the research here was unethical and escaped. He was caught immediately and turned into a test subject. He loathes the researchers very, very, very much.