Minami Minegishi, of the Japanese girl group AKB48, makes a public statement via YouTube, in this undated video. (AKB48/YouTube)

TOKYO - In a long list of publicity stunts thought up by Japan's most popular pop group AKB48, this may be the most bizarre. Or is it?

Minami Minegishi is one of the most popular idols in the 90 plus member super unit. The 20-year-old singer offered a tearful apology on YouTube Thursday, saying she shaved her head to atone for committing a cardinal sin - violating the group's no-dating rule.

The video, posted to the band's YouTube channel, followed a Japanese tabloid report claiming Minegishi spent the night at a 19 year-old boy band member's apartment. Published photos showing the star sneaking out of the building with sunglasses and mask covering her face set fans abuzz.

The nearly four minute confession that followed, began with a deep bow but ended with Minegishi sobbing and pleading to stay in the band.

Japanese girl group AKB48 perform on the stage during the 11th CCTV-MTV Music Awards Ceremony at MasterCard Center, Aug. 21, 2012, in Beijing, China. (AKB48/YouTube)

"I was supposed to set an example for younger members, but my actions were extremely careless and senseless," she said. "My mind has gone completely blank. I don't know what I can do or what I should do, but I couldn't bear to do nothing."

AKB48, made up of girls ranging in age from early teens to mid-20s, has developed a cult following in Japan with its bubblegum pop sound and a projected image of innocence, though their suggestive lyrics and Lolita like outfits suggest otherwise. Members cater to a predominantly male fan base, with a heavy emphasis on access and participation. They regularly hold "handshake" events, and their CDs come with ballots that enable fans to vote in an annual all member election, where top vote-getters are rewarded with more prominent roles in group singles and music videos.

The implied availability means the girls must adhere to strict rules of behavior, which includes no dating.

Minegishi claimed the decision to shave her head was her own, but online skeptics have questioned whether the clip was actually a publicity ploy orchestrated by Yasushi Akimoto, the producer behind AKB48. The apology amassed more than 4 million hits in one day.

The group is no stranger to controversy.

Last March, a television commercial featuring the girls seductively passing candy from mouth to mouth drew fire from viewers who complained it was "encouraging homosexuality." Last month, an AKB48 member was photographed naked with a young boy cupping her breasts from behind, prompting allegations of child pornography. Police launched an investigation and pulled the magazine featuring the photo from stands.

Another member caught in a crime of romance, was demoted to a regional sub-group as punishment, despite a public apology.

For now, Minegishi has been relegated to a trainee group, where she has vowed to start from scratch.

"I don't expect you to forgive me, just because (I shaved my head)," she said in the YouTube clip. "This is all entirely my fault. I apologize from the bottom of my heart."