Ninkyou Tensei: Isekai no Yakuza Hime

Ninkyou Tensei: Isekai no Yakuza Hime (任侠転生 －異世界のヤクザ姫－, Yakuza Reincarnation: Yakuza Princess of Another World) is a Japanese manga series written by Takeshi Natsuhara and Hiroki Miyashita and illustrated by Miyashita. It has been serialized in Shogakukan's seinen manga magazine Monthly Sunday Gene-X since July 2019, with its chapters collected into five tankōbon volumes as of May 2021.

Synopsis
Focuses on an old-fashioned yakuza member who made a career in the underworld. When he is caught in a trap and loses his life, he is reincarnated as a princess in a fantasy world. While now a beautiful girl, the yakuza still retains the values tempered from a life in a world without honor and humanity.

Don't bother Katagi ―――――― An old yakuza, Ryumatsu, who has a sima in Kabukicho, fell into the trap of his former younger brother and died. It was supposed to be, but she reincarnated into a princess in another world ...! ??

(Source: ANN)

Publication
Yakuza Reincarnation is written by Takeshi Natsuhara and Hiroki Miyashita and illustrated by Miyashita. It started in Shogakukan's seinen manga magazine Monthly Sunday Gene-X on July 19, 2019. Shogakukan has collected its chapters into individual tankōbon volumes. The first volume was released on January 17, 2020. As of May 19, 2021, five volumes have been released.

In July 2021, Seven Seas Entertainment announced that they had licensed the manga for English release in North America, to start publishing in March 2022.

In November 2021 Kazé announced that they had licensed the manga for French release in France, to start publishing in November 10, 2021.

Website:

 * Sunday-Webry
 * Manga-one
 * Happy Comic