Morning Musume or "Momusu" is an all-girl pop group that is notable for the way it periodically purges members (with "graduation" ceremonies designed to launch solo careers) and then replenishes its ranks through auditions. We are currently in the seventh year and sixth audition "generation" of the Momusu era, and the only member left from any generation before the fourth was YAGUCHI Mari (矢口真里). She's currently 22, which means she's been doing this job since she was in her mid-teens.

And yesterday, she suddenly retired. Why?

１５日発売の写真週刊誌「ＦＲＩＤＡＹ」にイケメン俳優・小栗旬（２２）との“連泊愛”を激写され、その責任を取った形。矢口はファクスで自らリーダー失格とファンに陳謝。現在、全国で展開中のモーニング娘。のツアーも辞退し、今後はソロ活動に入る。後任のリーダーは吉澤ひとみ（２０）が務める。
In the April 15th issue of weekly photo magazine Friday, her "repeated sleeping-together love" (連泊愛) with hunky actor OGURI Shun (22) will be paparazzilated (激写され）, and [her resignation] represents her taking responsibility for this. Yaguchi apologised to her fans by fax for disqualifying herself from the position as group leader. She has also withdrawn from Morning Musume's current countrywide tour, and will begin her solo career soon. YOSHIZAWA Hitomi (20) will succeed to the post of group leader.

Yep: no love for the Morning Musume girls, or it's curtains for them. This is a remnant of an older age of Japanese idoldom. Yaguchi sez:

「私にとってモーニング娘。はすべて。今回の騒動で私は『アイドル』として自分を裏切っていたと思います。」
"Morning Musume was everything to me. I realise now that I was cutting my own belly betraying myself as an idol [by getting involved in] this kind of trouble."

Oguri had no comment.