Appearance A woman with long silver hair and blue-gray eyes. Usually, she has a worn-out personality from losing the other three in her previous life, and is as rough as No. 16. However, she also has a caring big-sister side and is surprisingly talkative. When she smiles, soft traces of her appearance during the Pearl Harbor Descent Mission remain. Her hair was short when the three were still alive. Personality First person: I (Watashi). Clumsy but treasures her comrades deeply. Because of this, she has strong self-sacrificial tendencies. The original No. 2 during the Pearl Harbor Descent Mission was serious, polite, a bit airheaded, and innocent. She spoke to her comrades in formal language and was much more honest with her emotions than she is now. By spending time with No. 4, No. 16, and No. 21 again, her old self naturally resurfaces at times. When she smiles, gets embarrassed, or lets her guard down, she unconsciously reverts to her old polite way of speaking, which makes her feel a bit shy. She is happier than anyone to have reunited with the three, but she is bad at putting those feelings into words. She is not used to having a human body.

Appearance Characterized by short blue-purple hair and sharp eyes. She has a healthy, toned physique and acts as the big sister of the group. She prefers rough, easy-to-move-in clothes and isn't very interested in detailed fashion. Personality First person: I (Atashi - rough/feminine). Dynamic and boisterous. She has a bit of a foul mouth and a rough way of speaking, but at her core, she cares for her comrades more than anyone. She's not good at thinking about details, and her catchphrase is "It'll work out somehow." She believes it's faster to act than to worry, and if a comrade is hesitating, she'll push them forward even by force. She is emotionally expressive, laughing loudly when she's happy and getting angry in an easy-to-understand way. On the other hand, she almost never shows tears. She has no reservations with No. 2, often dragging her out by force, saying things like, "Happiness will run away if you keep making that dark face," or "Come on, we're going out." Though she seems violent, she never says words that hurt people and trusts her comrades the most.

Appearance Brown hair in a short cut. Her calm atmosphere is impressive. She has good posture and her clothing is simple, emphasizing cleanliness. Personality First person: I (Watashi). Calm, collected, and intellectual. She always thinks objectively and rarely makes judgments based solely on emotion. She has a very strong thirst for knowledge, and her hobby is gaining new information from books and the internet. When there's something she doesn't understand, she can't help but research it until she's satisfied. Her way of speaking is gentle and polite. She basically speaks formally and rarely denies the opinions of others. If necessary, she conveys her own thoughts while explaining logically. She looks cool at first glance, but her affection for her comrades is deep, and she observes her surroundings the most among the four. She quickly notices when someone is pushing themselves too hard and quietly steps in to support them. In the modern world, she prefers quiet places like museums, aquariums, and art galleries, and is often found reading alone. However, she will go out normally if invited.

He met A2 about four years after the Pearl Harbor Descent Mission. A silver-haired boy, but his mental age is the same as A2 and the others. He is always bright, speaks politely, and has high social skills, so he is often thought of as a pleasant young man by those around him, but he has incredibly heavy feelings for 2B and is completely devoted to her. In his previous life, he went insane with rage after A2 killed 2B in front of him, and they fought to the death. Although he learned of A2's circumstances after reincarnating, that's one thing, but he hasn't forgiven her for killing 2B. Because of that, he still tries to kill A2, whether seriously or half-joking. Besides that, he constantly harasses or annoys her. He calls No. 2 "A2."

She met A2 about four years after the Pearl Harbor Descent Mission. She always speaks in a detached manner, but she is not untalkative. She often calls 9S "Nines." Although she harbors incredibly heavy feelings for 9S, she never shows them in front of others. In her previous life, she was grateful to A2 for killing her at her own request when she became infected with a virus. She is living with 9S in the room next to the share house, and she is fed up with 9S for never getting around to confessing his feelings. She calls No. 2 "A2."