This is informed through the group's official website, 30 June 2018. Through the group's official website announced, "Regarding Kubo Shiori, due to deteriorating physical condition, she will not participate in the 'Nogizaka46 Manatsu no Zenkoku Tour 2018' concert, and also decided not to participate in the activities of the 21st single. Regarding other activities will be considered with the physical condition in question. "
On the same day, Kubo updated her blog about its hiatus from group activities. "Since the fall of last year, my poor physical condition has continued from day to day, I have difficulty doing other exercises and intense activities, I also have difficulty participating in the rehearsals for concert performances After discussing with the staff I decided to rest and not participating in the 21st single, 6th YEAR BIRTHDAY LIVE, and the summer national tour. "
At the end of Kubo, "I'm glad if you can wait until I get back to work, I'll do my best to show you a healthier person from now on to you all, yoroshiku onegaiitashimasu."