The story picks up with the protagonist, Octo, waking up feeling an unusual weight on her chest and stomach. She initially assumes it's Ayumu, a child who often sleeps in her bed at night due to nightmares. However, upon trying to push the weight off, Octo realizes she feels weak and the weight is heavier than expected. Sitting up, she conjures light from her palm, only to find herself in an unfamiliar room with straw on the floor and many other children sleeping around her. This leads her to suspect she's been kidnapped for human trafficking, though her mixed heritage makes this unlikely.
A child's voice calls out "Octo?" and she recognizes the boy as Kuro. However, Kuro appears significantly younger, around seven or eight years old, and Octo herself feels smaller than she should. Kuro dismisses her concerns, calling her "Chibi" (shorty) and implying she's always been small. Octo realizes she has also de-aged, questioning the effectiveness of her daily milk consumption. Kuro, unfazed, explains they are "orphan companions," a concept Octo struggles to grasp as she's no longer a child. She suspects time magic is involved, specifically mentioning Tokiwa, a mysterious figure with the nickname "Legal Loli."
Tokiwa's voice, though childish, confirms Octo's suspicion. She explains that Octo and Kuro have been transported to an "IF world," a past timeline where Octo chose to follow Kuro instead of being taken in by Asterisk. Octo's consciousness has temporarily entered the body of this world's Octo. Tokiwa warns Octo not to try too hard to recall memories, as it could lead to her consciousness becoming permanently fused with this timeline. Octo learns that in this world, Alpha, Kuro's mother, died of illness, and Kuro and Octo survived by stealing, eventually forming a child-only theft group.
Back in the present, Octo finds herself de-aged and in the same situation. Kuro is still present and they are part of a group of children living in an abandoned house in Kaokufu, a town in the Honni Empire. The town is described as having a significant wealth disparity, with a poor district near brothels where the children reside. Octo, now acting as the "child thief," takes on the role of cooking for the group, making French toast from donated milk and eggs.
The children plan to steal from a pirate ship, believing it to be less risky than targeting state-protected merchant ships. Kuro and another boy, Sole, have already infiltrated the ship. Octo is worried about the danger, especially since they are orphans with no one to help them if caught. Kuro explains the necessity of the heist due to the group's dwindling resources. Octo agrees to the plan, but Kuro decides she should stay behind to look after the younger children, believing her small stature and lack of magic would make her a hindrance.
When Kuro and the others don't return by nightfall, Octo, driven by worry, decides to go to the pirate ship herself. She confirms with Tokiwa that Kuro is alive in this timeline and that her actions are not problematic, as the "Octo of this time" would also act similarly. However, she is forbidden from using magic, as this world's Octo cannot use it.
Octo reaches the port and, unable to sneak onto the ship, calls out to a pirate. She discovers she's dressed as a boy in this world. She pleads with the pirate to return Kuro, claiming he is her brother and she has no one else. The pirate, indifferent, states the captain must agree. Octo offers her knowledge, specifically about a disease affecting the pirates, which she claims to be able to cure. This piques the interest of the vice-captain, Loki, whom Octo recognizes from her own timeline. Loki brings her to the captain.
The captain, revealed to be the Emperor's estranged half-brother, agrees to release Kuro and the others in exchange for Octo curing the pirates' scurvy. Octo, now effectively a hostage, works with the ship's cook to prepare meals. After two weeks, the pirates recover. The captain, impressed, offers Octo a position as the ship's pharmacist. Octo refuses, but the captain insists, revealing his motive: he needs people and resources to reclaim his position in the country, and sees Octo as a valuable asset. He offers to send Kuro to learn from a mechanic and Octo to a magic school on the Green Continent, promising to pick them up later.
Octo is then abruptly transported by Tokiwa to a different location and time. She finds herself in a dormitory room, realizing she's in a future timeline within the same world. Tokiwa explains that Octo's previous actions caused a "minor accident" and that she will be moving between timelines. Octo learns she is not imprisoned and is living with the "overprotective" Asuta, who treats her as his daughter. Asuta is now incredibly attentive, helping with cooking and doting on her.
Octo is brought to Asuta's workplace, the Royal Court Magicians' dormitory, where she is welcomed by a young man named List. She learns that in this timeline, she has been studying magic intensely, surpassing even her age group. She also learns that Asuta and End, a powerful elf, are rivals. End teases Asuta about his possessiveness over Octo, even suggesting he wants to marry her.
Later, Octo is called to the captain's office, where she finds Asuta, End, and surprisingly, Camus, the First Prince. The captain is upset that his ship was burned and demands compensation. Octo offers information on preventing scurvy, which she had previously learned. Asuta, angered by the pirates' actions, wants to attack them, but Octo intervenes, appealing to his desire to stay together. Asuta agrees to spare the pirates and offers to send Kuro to learn from a mechanic and Octo to a magic school.
Octo is then transported again, finding herself back in a pirate's hideout, but this time it's the past. She learns that the pirates attacked Asuta's ship because they believed he had kidnapped his own daughter. Octo intervenes, stopping Asuta from attacking the pirates and revealing herself to him. Asuta, relieved and overjoyed, embraces her. He then uses his magic to dissipate the storm clouds and lightning.
Asuta, now extremely protective, insists on taking Octo home and keeping her confined. Octo, fearing a life of isolation, tries to stall by claiming she's treating sick pirates. Asuta agrees to let her finish, but his possessiveness is evident. Octo then asks Asuta to teach her to read and write, which he readily agrees to, seeing it as a way to keep her close.
The story continues with Octo in a new timeline, at the Royal Palace, where she is being taught by Asuta and his colleagues. She learns that Asuta is extremely doting and protective, and that End, the elf, is a rival for Asuta's attention. Octo's presence in Asuta's workplace is accepted due to her exceptional magical talent, which prevents her "mixed-blood" nature from causing issues.
The narrative then shifts to a scene where Octo is making crepes for Asuta's colleagues. List, one of the colleagues, expresses his gratitude and pleads with Octo to stay, stating she's the only one who can manage Asuta and End's rivalry. Octo is then confronted by Asuta and End, who are arguing over her. Octo tries to mediate with her crepes.
Later, Asuta and End are arguing again, this time about Octo's future. The First Prince and Third Prince, Mika, arrive. Mika, who seems to have a crush on Octo, declares she will be his bride, much to Asuta's anger. Octo, realizing the potential for disaster, tries to de-escalate the situation by stating she wants to study magic. This leads to a discussion about her attending magic school.
Octo is then transported again, finding herself back in the pirate hideout, but this time it's the past, and she's been captured by pirates. She learns that Asuta is furious about the pirates burning his ship and attacking his crew. Octo intervenes, offering to teach the pirates about scurvy prevention in exchange for their release. The captain agrees, but Asuta is still angry.
The story concludes with Octo being transported to a new timeline, where she is at the Royal Palace, studying magic. Asuta is extremely protective, and Octo is trying to navigate her relationships with him, End, and the princes. She realizes that her actions have led to a complex web of relationships and potential futures, and that her journey is far from over.
