The 4th Hierarchical City of Naobi is a Hierarchical City, home to the Yayoi family of the Duodecim. In the Ikaruga Civil War, it was the location for the Phenomena Weapon Dispossession Operation.
Naobi was formed shortly after the Dark War, and was visited by Nine the Phantom and Celica A. Mercury - together, they buried the Deus Machina: Nirvana deep within the city so that it would not be accessed by other's in the future. They sealed Nirvana in a coffin that stood close to the city's Cauldron. The Novus Orbis Librarium discovered its location in 2195, resolved to excavate the Nox Nyctores. Relius Clover was made aware of this, and contacted Sector Seven. Sector Seven sent a mercenary squadron undercover to the city in an attempt to steal it from under the NOL. Although the mission was a success, the city became a grave for most of the mercenaries.
Bullet later visited the city to investigate the details of the operation and found the remains of the excavation site.
In 2200, Naobi was reconstructed within the Embryo. The remaining Duodecim and Homura Amanohokosaka were sent to the Yayoi's estate in Naobi, where Hibiki Kohaku and Mai Natsume protected them under Kagura Mutsuki's orders. 
People born in Naobi
People living in Naobi
- Yayoi family
- Tsubaki Yayoi
- Tsubaki Yayoi's father
BlazBlue: Central Fiction Library Entry
- 4th Hierarchical City 'Naobi'
One of the Hierarchical Cities.
Details are unknown. This is also the home city of Tsubaki. 
Naobi is named after the Japanese deity Kamunaobi-no-Kami, a deity created when Izanagi-no-Mikoto cleansed himself of a curse after he left Yomi.
- ↑ BlazBlue: Continuum Shift Extend, Story Mode, that which is inherited
- ↑ BlazBlue: Chrono Phantasma Extend, Story Mode, Kokonoe "Collisions", Prologue
- ↑ BlazBlue: Chrono Phantasma Extend, Story Mode, Bullet "The Rat", Chapter 3 - 4th Hierarchical City: Naobi
- ↑ BlazBlue: Central Fiction, Story Mode, Episode 010, Chapter 080, Sub Scenario 1
- ↑ BlazBlue: Central Fiction, Library Mode, Location #008