The Takakura siblings are enjoying Takoyaki together and happy with the news that Himari will soon be released from hospital when the magic hat posesses Himari again for another Survival Strategy meeting with her brothers and insists that their ordeal will not be over until the Penguin-Drum is retrieved. Meanwhile, Yuri and Tabuki reminisces about their childhood days with Momoka and while Yuri is unable to forgive the siblings for their parents' crime, Tabuki tries to dissuade her. In the next day, Himari leaves by herself with Ringo for shopping much to Kanba and Shouma's despair as they are informed that she must take another dose of her medicine before sunset. While the brothers look for Himari, Ringo receives a call from Yuri who invites her and Himari for a meeting. Yuri waits for Himari, but is intercepted by Masako instead, and the two start fighting for the two halves of the diary, while Himari and Ringo are approached by Tabuki who invites them to a construction site where he claims he will finally bring punishment to the Takakura family.

Tabuki reminisces about how he injured his own hands in despair of being relenquished by her mother as she only cared about his younger brother who was a much better pianist than him. After Tabuki traps Ringo at an elevator and holds Himari hostage, he phones Kanba demanding to bring his father to him. Kanba arrives alone to meet them, claiming he has no idea where his father is and finds Himari hung over into a construction bucket. Tabuki does not believe him and Ringo decides to call the police, but Kanba asks her to not do it and she calls Shouma instead. Tabuki reveals that Himari's brother is receiving money from his father's organization to pay for her treatment, and remembering about how Momoka had her hand severely injured to save him, Tabuki starts severing the wires holding the bucket one by one, claiming thet the only way for Kanba to prevent Himari from falling to her death is by sacrificing his own hand to hold the final wire together when it snaps. Kanba does so and despite his pain, he claims he would never have his sister die. Himari than decides to jump by herself to spare Kanba's life, but Tabuki saves her from the fall after seeing in Kanba the same determination to protect his sister he saw in Momoka when she saved him. Shoma arrives soon later and the siblings reunite in tears while Tabuki makes his leave, meeting Yuri on the way who reprimands him. It is also shown that Yuri's showdown with Masako ended in a draw, as each one still holds a half of the diary.

After the incident at the construction site, Tabuki quit his job and leaves Yuri, while Kanba is praised by his parents for protecting Himari, claiming that once their true objective is reached, they will become together again. Kanba makes use of some money he got from them to throw a party for Himari with Shouma and Ringo to celebrate her return home, while Himari wonders about her conversation with Sanetoshi as she doubts that she will eventually be cured. He also has a conversation with Masako, who reaffirms her intentions to stop his plans. Masako then pays a visit to Himari and demands her to remember about her true past, as she claims Himari is not Kanba's real sister. She points a gun that in opposite to her usual memory-erasing bullets, contains memory-regaining ones, but is stopped by Kanba and Shouma who had just returned home. However Himari manages to remember her past and realize that her soulmate is actually Shouma.

Masako decides to leave the Takakuras alone, still not accepting the 'family' they have. As Himari has another conversation with Sanetoshi, Shouma confesses to Ringo that Himari is not actually his blood sister. Years ago, whilst his parents were organising to change the world with their organization, Shouma met the orphaned Himari whilst exploring his condo. Whilst she is initially passive of him, the two grew a friendship over an abandoned kitten they find, up until it ended up being taken away. When Shouma discovered that Himari had headed over to the 'Child Broiler', where unneeded children go to disappear from the world, he rushed over there to rescue her and chose her to become a part of her family. Back in the present, Kamba continues to converse with his parents about what needs to be done to change the world.

Ringo is approached by a journalist asking about the Takakura siblings, but she avoids him and warns Himari about him. Later that night, Himari, who was told by the same journalist about how Kanba have been collecting money for her treatment, trails him to the shop where he supposedly meet his parents just to find the place torn down and have a shocking revelation. Shouma is informed by the journalist about Kanba's involvement with the Kiga Group and tries to stop him by force with no success. Meanwhile, Tabuki and Yuri also reach the shop and just like Himari, find the skeletons of the Takakura couple before being attacked by an unknown assailant. Shouma, who finds that Kanba ordered the journalist to be killed in a car accident, and was informed by Sanetoshi that the medicine will not prolong Himari's life for long, informs her that they can't live as a family anymore and sends her to live with his uncle. Later the Kiga group, whose true leader is actually Kanba prepares themselves to make a large scale operation, and Himari, seen standing next to him, claims that she is determined to stop him at the cost of her life.

Ringo stumbles on two girls dressed suspiciously standing before the Takakuras' house and finds that they are actually Himari's childhood friends Hibari and Hikari from the Double-H idol duo. They ask her to give Himari a present in return for the scarves she knit for them before leaving. Kanba learned from Sanetoshi that his medicine will not work on Himari anymore, and that according to him, she can only be saved after he fulfills his group's objective. Himari tries to dissuade him with no success and discovers that his hideout is situated under the aquarium where she first died. She prays for God to have Kanba saved in exchange for her life and falls lifeless on the ground. Yuri calls Ringo and returns her the half of the diary in her posession and stays beside an unconscious Tabuki at the hospital, who was stabbed by the attacker who was revealed to be Yuri's former lover and co-worker. Masako tries to convince Kanba to give up as the police is already aware of his plans and has a warrant on him, but he moves forward ignoring her pleas until they are surrounded and he puts himself im harm's way to protect her. Injured and unconscious, Kanba is carried away by his comrades while Masako decides to confront the police by herself to cover his escape.

On the day of the terrorist attack, 16 years before, Sanetoshi is contronted by Momoka who was determined to stop him and while her spirit ends up split in two with each half becoming the penguin hats used by Himari and Mario, his is divided into the two black rabbits that always accompany him. Back to the present, Shouma is informed that Himari's life is at its end and Ringo conforts him while Kanba is taken by Sanetoshi to a gravely injured Masako and brings her from the dead before his eyes. Despite Masako's pleas, Kanba leaves with Sanetoshi to continue his plan, carrying her half of the diary with himself. Shouma sees a vision of Himari asking him to stop Kanba, and when his brother comes to fetch her, he is shot unconsious by him with a penguin bullet. Ringo is called by Kanba to the aquarium and a bomb explodes knocking her out. Sanetoshi watches her struggling to stop her half of the diary from being burned out and after she fails, he has Kanba burn the other half. Shouma wakes up and manages to reach Kanba determined to stop his plans.

Shouma tries to dissuade Kanba with no success while Ringo also boards the train, claiming she had learned from the present she got from Himari's friends the secret spell contained into the now lost diary. She activates the spell determined to sacrifice herself to save Himari and the others, but Shouma takes the burden to himself instead while Kanba sacrifices himself to ressurect Himari for good. The terrorist attack is stopped and both Himari and Ringo are found unconsious with no memories about the brothers or everything that happened. The same occurs for Masako whose brother Mario also fully recovers. While hanging with Ringo at her house, Himari finds a message left by Kanba and Shouma and starts crying without knowing the reason why while Shouma and Kanba, in children form, pass in front of her house accompanied by the four penguins.