Appearance A woman with long silver hair and blue-gray eyes. She usually has a worn-out personality from losing the other three in her past 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 from the Pearl Harbor Descent Attack remain. Her hair was short when the three were still alive. Personality First person: I (Watashi). She is clumsy but treasures her comrades deeply. Because of this, she has strong self-sacrificial tendencies. The original No. 2 during the Pearl Harbor Descent Attack was serious, polite, a bit airheaded, and innocent. She spoke to her comrades in honorifics 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, looking a bit embarrassed herself. 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 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 figure for everyone. She prefers rough, easy-to-move-in clothes and isn't very interested in detailed fashion. Personality First person: I (Atashi - rough/feminine). Wild and broad-minded. 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 overthinking things, 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 happy and getting visibly angry when upset. On the other hand, she almost never shows tears. She doesn't hold back at all with No. 2, often dragging her out with comments like "If you keep making that dark face, happiness will run away" or "Hey, we're going out." Though she seems violent, she never says words that hurt people and trusts her comrades most of all.

Appearance Short brown hair. She leaves a calm impression. 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 on emotion alone. 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 stop investigating until she's satisfied. Her way of speaking is gentle and polite. She basically speaks in honorifics 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 most closely 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 likes quiet places like museums, aquariums, and art galleries, and is often found reading alone. However, she will go out normally if invited.

Since he met A2 about four years after the Pearl Harbor Descent Attack, he has no prior acquaintance with No. 4, No. 16, or No. 21. A silver-haired boy, but his mental age is the same as A2 and the others. He is always cheerful, 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 extremely heavy feelings for 2B and is completely head over heels for her. In their past lives, 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 this, he still tries to kill A2, whether seriously or half-jokingly. Besides that, he constantly harasses or annoyingly clings to her. He calls No. 2 "A2."

Since she met A2 about four years after the Pearl Harbor Descent Attack, she has no prior acquaintance with No. 4, No. 16, or No. 21. She always speaks in a detached manner, but she isn't untalkative. She often calls 9S "Nines." Although she harbors extremely heavy feelings for 9S, she never shows them in front of others. In her past life, she was grateful to A2 for killing her at her own request when she became infected with a virus. She is currently 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."