In the previous series, Hana and Kazuma fell in love after a fateful encounter, but when the family of thieves was put on the nation's most wanted list, they decide to say their goodbyes forever, even though they loved each other... However, in the final episode, they were finally together due to a rumor that the family of thieves is assumed dead. The new sequel continues from this fateful conclusion, as after overcoming many obstacles, Hana and Kazuma are finally able to live the life they had dreamed of as newlyweds...
The Mikumo family, known as the "L family" and whose family business is thievery, had deceived the public into believing they were all dead and were staying at the home of Hana's (Kyoko Fukada) boyfriend, Kazuma Sakuraba (Koji Seto). However, the Sakuraba family were police officers. Meanwhile, in Kyoto, middle school student Hojo Mikumo (Hashimoto Kanna) was receiving detective training from her grandfather and head of the family, Soshin (Ibuki Goro), at the Hojo family home, a family of famous detectives.
Hana Mikumo (Kyoko Fukada), the daughter of a family of thieves, decided to separate from her husband, Kazuma Sakuraba (Koji Seto), a detective, believing that building a family with her would ruin his life, and she intended to raise their child alone. Kazuma searched for Hana but was unable to find her. Hana, surrounded by her family, including Takeru (Atsuro Watabe) and Etsuko (Shinju Ozawa), was approaching her tenth month of pregnancy. Meanwhile, Mikumo Hojo (Kanna Hashimoto), now a high school student, moved to Tokyo with her butler, Saruhiko Yamamoto (Tatsuya Gashuin). Having lost her fortune, Mikumo lived in a dilapidated apartment while pursuing the "L family."
Hana Mikumo (Kyoko Fukada) safely gives birth to a child with Kazuma Sakuraba (Koji Seto). However, since Kazuma is still being monitored by the public security police for his involvement with the "L family," he is required to appear single and live with Hana and her family only on weekends. As a result, the child is named "An Mikumo," taking the surname of the "L family." Time passes, and An, who has grown up showered with love not only from the Sakuraba family, including Norikazu (Masayuki Shinta), but also from the Mikumo family, including Takeru (Atsuro Watabe) and Etsuko (Shinju Ozawa), is now an elementary school student (Nono Obata).
Hana Mikumo (Kyoko Fukada) is terrified that Anzu (Nono Obata) will find out that the Mikumo family's business is thievery. Hana intends to leave the life of crime behind, and Anzu is growing up to be a good girl, but Takeru (Atsuro Watabe) and his gang's passion for thievery is unstoppable. Meanwhile, Mikumo Hojo (Kanna Hashimoto) suspects a connection between the "L family" and Kazuma Sakuraba (Koji Seto) and goes to the Sakuraba house.
Someone filmed Hana Mikumo (Kyoko Fukada) escaping in her thief's outfit. Takashi (Atsuro Watabe) dispatches Ladybug 3 Investigation Team to pinpoint the filming location. Following the motorcycle tire tracks left there, they locate the culprit's hideout. The video transmitted by Ladybug 3, who has infiltrated the hideout, shows Futaba Miwa (Minami Tanaka), a female thief they once fought. Miwa had escaped from prison with the help of her henchmen, Oiwa (Tomoaki Honma) and Yoda (Togi Makabe), for a certain purpose. Takashi plans to infiltrate the hideout to destroy the evidence that the "L family" is still alive.
As Anzu (Obata Nono), the daughter of Mikumo Hana (Fukada Kyoko) and Sakuraba Kazuma (Seto Koji), is on her way to school, Hojo Mikumo (Hashimoto Kanna) suddenly appears before her. Anzu reacts to a picture of Kazuma that Mikumo shows her, exclaiming, "That's Daddy!" Suspecting that Anzu is the child of Kazuma and a daughter of the "L family," Mikumo tries to press her further. However, she manages to escape the predicament thanks to Ladybug No. 3, the bodyguard, sent out by Wataru (Kurihara Rui). An alarm signaling an emergency blares through the "L family" apartment building, but Wataru tries to deceive Hana, Takeru (Watabe Atsuro), and the rest of the family by telling them it was a false alarm. However, Takeru notices that Wataru is acting strangely.
Finally, Mikumo Hana (Fukada Kyoko) and Hojo Mikumo (Hashimoto Kanna) face off! Hana defeats Mikumo and successfully erases her memory of meeting her with a memory-erasing spray. However, she is worried that the "L Family" is still being cornered. The next morning, when Mikumo comes to work, Kazuma (Seto Koji) asks her about what happened the day before, but Mikumo says she doesn't remember. Of course, she's lying. She had prevented the memory-erasing spray from entering her body and maintained her memory.
Hana Mikumo (Kyoko Fukada) has her secret—that they are the "L family"—revealed to her daughter, An (Nono Obata). Meanwhile, Kazuma Sakuraba (Koji Seto), struck down by the deadly blade of Natasha (Rina Ota), a hitman employed by the gang of thieves, is taken to the police hospital. Kazuma is watched over by Norikazu (Masayuki Shinta), Misako (Marcia), their daughter An, and Mikumo Hojo (Kanna Hashimoto), who accompanied him from the crime scene. However, Hana and the others, who are actually still alive and causing a stir in the world by committing robbery and murder, cannot rush to Kazuma's side. All they can do is pray, but their prayers are in vain as Kazuma goes into cardiac arrest. The "L family" is cornered in a desperate situation.
Peaceful days had returned to the family of Hana (Kyoko Fukada), Kazuma (Koji Seto), and An (Nono Obata). Mikumo Hojo (Kanna Hashimoto) had also regained her quiet life after her noisy neighbors moved out. Meanwhile, Etsuko (Shinju Ozawa) was on the verge of collapse due to a lack of treasure. Then, Wataru (Louis Kurihara) offered her a new treasure: "Grace Kelly's beloved Cartier diamond ring." At that moment, Teru Enjoji (Yusuke Onuki) appeared at Hana and Kazuma's apartment. Enjoji asked Hana to pretend to be his fiancée for just one day. Enjoji was scolded by his father, Go (Ichimura Masachika) for not yet marrying his fiancée, Hana. When Hana and Enjoji met with Go, he was pressed for answers about the wedding date and wedding dress. Enjoji was then ordered to steal a ring for Hana that was traditionally given to brides in the Enjoji household. It was the same Cartier diamond ring that the "L family" had been after, the one loved by Grace Kelly.