Pop idol Rino Sashihara, a popular member of AKB48 affiliate HKT48, said Saturday she will leave the sister group next year after a graduation concert in April.

"I, Rino Sashihara, will graduate from HKT48," the teary entertainer said during a concert in Tokyo, according to entertainment information site Oricon News. "I will do my utmost as an idol until the last days of Heisei."

Sashihara will leave the group, based in Fukuoka, after an April 28 concert in Yokohama. She will then hold an event with her local fans in Fukuoka on May 28, she said.

After her debut with AKB48 in March 2008, Sashihara quickly became popular in the group but was transferred to HKT48 after a weekly magazine reported in 2012 that she had a past relationship with one of her fans. Members of AKB48 and its affiliates are strictly banned from engaging in romantic relationships, a rule that has triggered public criticism.

Despite the setback, she won AKB48's annual election, a fan-based vote televised live nationwide, four times — once in 2013 and three years straight from 2015. Sashihara currently appears regularly on various variety TV programs.