2022: Formation

On June 29, following OCHA NORMA's debut, the Hello Pro Kenshuusei Unit was revived with five new Kenshuusei members under the name Hello Pro Kenshuusei Unit '22. The members were revealed to be Matsubara Yulia, Onoda Karin, Hashida Honoka, Murakoshi Ayana, and Uemura Hasumi.

On August 28, the unit performed at @JAM EXPO 2022.

On November 30, they performed as opening act of the ANGERME concert 2022 autumn final ANGEL SMILE.

On December 10, they performed as one of the opening acts of the Morning Musume '22 25th ANNIVERSARY CONCERT TOUR ~SINGIN' TO THE BEAT~ Kaga Kaede Sotsugyou Special.

2023

On May 23, it was announced that Yoshida Hinoha and Kamimura Rena would be added to the unit. It was also announced that Hello! Project is planning to debut a new Hello! Project group in 2024, with the members from Hello Pro Kenshuusei Unit '23 confirmed as members. As the new group will be solidifying its composition, the members will be promoting under the Hello Pro Kenshuusei Unit '23 name for the time being.

2024

On June 16, at the Hello! Project Kenshuusei Happyoukai 2024 6gatsu "Lily", it was announced that the new group would be named Rosy Chronicle, and two additional Hello Pro Kenshuusei members would join the group: Shimakawa Hana and Soma Yume. The group will start their activities under the new formation at the Hello! Project 2024 Summer ALL OF US tour on July 13.

On June 18, all of the members' profiles were removed from the Hello Pro Kenshuusei page on the official Hello! Project site, indicating they were no longer trainees.

On July 11, it was announced that Hashida Honoka was appointed as the leader of Rosy Chronicle.

GROUP NAME ORIGIN

The name Rosy Chronicle (ロージークロニクル) comes from the words "Rosy" (ロージー) and "Chronicle" (クロニクル). "Rosy" means "rosy" and "full of hope" and "full of happiness", and "Chronicle" means "chronicle," a history book that chronicles events year by year. Therefore, the combined name of Rosy Chronicle is derived from the hope that the history of Rosy will be passed down from generation to generation.