Personally, I wouldn't call it J-pop. It's more like J-hip-hop.
2021.09.08 Release 29th Single 「We Just Go Hard feat. AK-69」 / 「EUPHORIA」 https://www.j-storm.co.jp/s/js/discog...
Download & Streaming https://KAT-TUN.lnk.to/213OsChb
KAT-TUN is a music group from Japan.
The group's name was originally an acronym based on the first letter of each member's family name: Kazuya Kamenashi, Jin Akanishi, Junnosuke Taguchi, Koki Tanaka, Tatsuya Ueda, and Yuichi Nakamaru. Their debut on March 22, 2006 was marked by a tripartite release of a CD single, album and music DVD on their exclusive record label J-One Records. Since then, all of their single, album and music DVD releases have debuted at number one on the Oricon music and DVD charts.
Today The group is reduced to 3 members :
AK-69 is a Japanese Hip Hop artist, also known as Kalassy Nikoff (エーケーシックスティーナイン／カラシニコフ) . Officil website : https://ak-69.jp/
As a rapper, AK-69 uses his stage name; while singing, he is usually known as "Kalassy Nikoff." AK-69 also goes by the alias "REDSTA." In 2004, he began producing a fashion line known as "BAGARCH." The single "Public Enemy" was nominated in 2011 for Best Hip Hop Music Video in the MTV Music Aid Japan and won the same award at the 2011 Space Shower Music Video Awards.
The Independent Artist of the Year award was presented to AK-69 at the 2011 Billboard Japan Awards.
Rather than labelling all of the groups or artists as Jpop or whatever they're doing, Japanese music needs to include more J-music genres.