Kitakyushu (lit. North Kyushu City) is the northernmost city on the island of Kyushu. After Fukuoka, it is the second largest city in both Fukuoka Prefecture and Kyushu. The city was formed in 1963 following the merger of several independently-governed districts, including the historic city of Kokura (小倉市 Kokura-shi). Several locations in Kokura are visited and named in the Hakata Tonkotsu Ramens light novels, and some, both real and fictional, are recurring settings throughout the series.
Locations within Kokura
Kokura Prefecture was founded separately from Fukuoka Prefecture in the 1870s but soon after assimilated into the larger prefecture. The city of Kokura was founded in 1900. When Kitakyushu was established in 1963, Kokura merged with the city and was divided into Kitakyushu's two central wards, Kokurakita (小倉北区 Kokurakita-ku lit. Kokura North) and Kokuraminami (小倉南区 Kokuraminami-ku lit. Kokura South).
Kokura is Shunsuke Saruwatari's hometown. After he quits his job at the Tokyo branch of Murder, Inc., he returns to Kyushu and makes a name for himself in Fukuoka Prefecture as the Submarine Ninja. Naoya Nitta, who also grew up in Kokura, stayed in the city and has been making a living for himself as a killer consultant.
Lady Madonna is a darts bar in Konya City (紺屋町 Konya-machi), a small nightlife district in Kokura. The owner of the bar is a killer mediator, and the basement of the establishment has a separate bar for killers and dealers to gather and a practice range with several human dummies for the hitmen who socialize there.
Kokura Station Plaza
Kokura Station sits several city blocks away from Lady Madonna. After Saruwatari's initial rejection at the bar, he is walking through the station plaza when Nitta reaches out to him.
Uomachi shopping district
The Uomachi shopping district houses an arcade near Heiwadori Station and shares a border with Konya City. When Saruwatari and Nitta meet again after several years, Nitta brings Saruwatari to a sukesan restaurant in the arcade, and the two discuss business, with Nitta offering to be Saruwatari's consultant.
Mihagino is a neighborhood in Kokurakita. After agreeing to work with Nitta, Saruwatari is tasked with eliminating a short list of small organizations, the last of which are housed in a cheap apartment building in Mihagino.
Ogura is a neighborhood of Yahatahigashi Ward and a suburb of the historic city of Kokura. Presumably within Ogura, Ogurakita High School is the fictional high school that Saruwatari and Nitta attended in the anime, and they meet again for the first time in several years on the school's baseball field. Additionally, in the anime, Saruwatari and Nitta's grasslot baseball team is the Ogura Fried Udons, indicating that they still live in the same suburb in which they grew up.