Isekai Yakuza ~Gokudou desu ga Teni Shitara Kyuuseishu ni Narimashita~

Alternative

異世界ヤクザ～極道ですが転移したら救世主になりました～; Isekai Yakuza - Gokudou desu ga Ten'i Shitara Kyuuseishu ni Narimashita; I'm a GOKUDOU, but after teleporting to the another world, became a savior.; Another World Yakuza ~Even a Gokudo Can Become a Savior When Tranported to Another World~