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.
