Rino Sashihara, a leading Japanese idol singer, will leave the all-girl musical group HKT48, an affiliate of the country's entertainment giant AKB48, next year, she said Saturday.

Sashihara, a 26-year-old four-time winner of the AKB48 family's annual popularity contest, made the announcement during a concert in Tokyo by the group based in Fukuoka, southwestern Japan.

"I decided (on leaving) a long time ago," a tearful Sashihara told the audience during the concert.

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Sashihara's last concert will take place at Yokohama Stadium on April 28, 2019, and she will take part in an event with her fans at Marine Messe Fukuoka in Fukuoka on May 28 of the year.

"I am sorry for the surprise. But I will do my best to enjoy myself as an idol singer until the last minute of the Heisei era," she also said in a tweet. The name of the Japanese era will change from Heisei after Emperor Akihito abdicates on April 30.

Sashihara who hails from Oita, near Fukuoka, has been a leading member of the AKB48 family even after she transferred to the HKT48 from the core group in 2012.

She has served as tourism ambassador for her hometown as well as emceeing variety shows on TV.

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