|Name:||9th Hierarchical City of Akitsu-Kō|
|Rōmaji:||Dai Kyū Kaisō Toshi "Akitsu-Kō"|
The 9th Hierarchical City of Akitsu-Kō is situated in Russia and is the birthplace of Trinity Glassfille.
Being the 9th Hierarchical City means that Akitsu-Kō is most likely bigger than Kagutsuchi.
The Librarium Branch in Akitsu-Kō was destroyed by Ragna the Bloodedge during the first chapter of Chimelical Complex and the first episode of BlazBlue: Alter Memory. This is later shown to have a startling effect on the ecosystem as the weather control enforced by the Librarium ceases to function.
The Cauldron that was placed here was being used for smelting. Ever since its destruction, the weather control system had become nonoperational. In BlazBlue: Chronophantasma, it was resuscitated by Relius Clover.
The 10th Hierarchical City of Akitsu-Otsu is located right beside this city, the two together from a pair and are simply refereed to as Akitsu. They form one of the tree pairs of the twin Hierarchical Cities. Akitsu-Kō's broken weather system is also influencing Akitsu-Otsu.