Not in Textbooks 4

Four years have passed since that emotional marriage proposal at Tsukushi Makino's high-school prom, and Tsukasa Dōmyōji announced his engagement to Tsukushi to the entire world. At an engagement dinner between their families, Dōmyōji's mother, who has been strongly against their relationship before, presents Tsukushi a tiara, which is estimated to be worth roughly 10 billion yen, as a token of their engagement. But that night, the tiara is stolen by somebody! Then, Dōmyōji and Tsukushi travel around the globe to Las Vegas, Hong Kong, and even a deserted island to get the tiara back—the legendary tiara that has been believed to "bring eternal love." In the meantime, where and what are the "F4" fellows, who have just gone separate ways, doing now?

Problem student Haru Yoshida sits next to the cold and studious Shizuku Mizutani in class. Without any other friends to turn to, both of them start to get to know each other and grow closer. Haru eventually develop feelings for Shizuku and confesses his feelings to her. Will Haru and Shizuku get their happily ever after?

Hatori Matsuzaki is a female high school student. She has a crush on her childhood friend Rita Terasaka and believes he will eventually choose her as her heroine, but Rita Terasaka begins dating Miho Adachi. Meanwhile, the most popular male student, Kosuke Hiromitsu takes an interest in Hatori Matsuzaki.

Raku Ichijo (Kento Nakajima) is an only son and a high school student. His father is the leader of yakuza group Shuei-gumi. Raku Ichijo doesn't like to fight and he studies hard. His dream is to become a public official. One day, he passes the entrance gate at his high school and is kicked inadvertently by Chitoge Kirisaki (Ayami Nakajo). She is a new transfer student at the school. Chitoge Kirisaki is the only daughter of a rival gang leader. To keep the peace between the rival gangs led by their fathers, Raku Ichijo and Chitoge Kirisaki decide to act as boyfriend and girlfriend. --asianwiki

Arata Kaizaki, a jobless adult, undergoes an experiment that makes him 10 years younger. He goes back to high school and falls in love with Chizuru Hishiro, who is more than she seems.