[Rumor] Adopted by Yakuza ?

[Andrenekoi]

In 1973 Tetsuya Katō, Misora's brother, was prosecuted for gang-related activity. Although NHK did not acknowledge any connection, Misora was excluded from Kouhaku uta gassen for the first time in eighteen years.[7] Offended, she refused to appear on NHK for years afterwards.[7]

I guess if Ayu was part of Yazuka (something really hard to hide for more than 10 years), she wouldn't be performing at Kouhaku too Considering that Hibari was the biggest japanese singer of that time (and considered the biggest overall)