I don't think anyone here at AHS cares about this - it may be better suited to the
Stage48 forum - but Hirate Yurina, the ace of Keyakizaka46 (which is a sister group of Nogizaka46, which is derived from AKB48), suddenly left the group on Thursday. She was only 18 years old. Techi-san centered all eight singles that Keyakizaka46 released so far (dating back to April 2016 when she was only 14), but there has been concerns about her health, especially after what happened in the 2017 Kouhaku, when she and two other members - Suzumoto Miyu, who also announced graduation on the same day as Techi's resignation announcement, and Shida Manaka, who graduated early last year - fell after the group performed "Fukyouwaon" (4th single) twice, and put her and the entire group into a lot of scrutiny. While the management declined to reveal her reason why she left Keyakizaka46 (as a withdrawal rather than a graduation that we typically see in Japanese idol groups big and small, including AKB48, Nogizaka46, Hello! Project and even 'underground' acts), and she declined to comment further than the announcement before her Thursday night Girls Locks! segment of Tokyo FM's School of Lock!, people have been speculating that the combination of her previous health issues - sacroiliac joint instability, to be specific - and rumored disagreement between her and the management may have led to her withdrawal from the group.
(EDIT: These reasons could be related, as she felt too much pressure and carried too much burden of being the absolute 'ace' position that she had, and combined with the health issues, I'm sure that may have been over the limit for her.)
Hirate was the lead actress in the movie "Hibiki" (as Hibiki herself, Akui Hibiki) last year.
(In addition to Hirate and Suzumoto leaving Keyakizaka46 on Thursday night, Oda Nana also graduated from the group, but unlike Hirate and Suzumoto, which was primarily health reasons, Oda was caught in a dating scandal during the summer of last year and has struggled with Keyakizaka46 since, and she is citing that and her focus on graduating from college as the reason why she is leaving the group. Sato Shiori, while not leaving Keyakizaka46 at the moment, also announced her intentions to go on hiatus as she focuses on overseas studies.)
It really stinks to see a group getting crippled by mismanagement. It's not the first time we saw a group as such, but for a group like Keyakizaka46, I don't know why the management has been betting a bit too much on Hirate Yurina, causing her to overwork during her tenure with the group. Hopefully we see brighter futures for both Keyakizaka46 (minus Techi) and Techi herself, maybe Techi can show off her own skills to her full potential while Keyakizaka46 regroups themselves moving forward with a mix of old (1st gen, some already graduated but some are still staying) and new (2nd gen, introduced just last year but already getting some work) faces.
(EDIT: I'm hearing Techi might go solo sometime later this year! But she needs to get some rest before she goes back into action.)
(Keyakizaka46's last single that they released was back in February 2019. They were supposed to release one late last year or early this year with Hirate as center again, but with all these circumstances, it's pretty much delayed indefinitely at this point, while the management will have to review how they will have to move forward without her before pushing ahead for their long-delayed ninth single.)