Qin Shi Mingyue: Tian Xing Jiu Ge
Japanese title: 秦时明月 姐妹篇：天行九歌
Alternative titles: Qin's Moon: Nine Songs of the Moving Heavens, The Legend of Qin: Nine Songs of the Sky
Type: ONA
Source: Original
Episodes: 60
Status: Finished Airing
Aired: Mar 10, 2016 to Jul 5, 2018
Duration: 18 min per ep
Rating: PG-13 - Teens 13 or older
Studios: Sparkly Key Animation Studio
Genres: Action, Fantasy
Themes: Historical, Martial Arts

Facing the threat of the Qin State, danger seems to lurk within the Han State, which is known as the weakest out of the Seven States. Unknown to the Han Emperor, that very threat is the Great General of Han, Ji Wuye. Working under the Great General are the Four Fearful Warriors of Nightfall.

Each four specialized in military, finance, politics, and espionage. In hopes of creating a new Han State, Quicksand was formed by Han Fei, the ninth prince of the Han. With Wei Zhuang, Zhang Liang, Zinü, and Nong Yu, they support the Prince in realizing the goal of Quicksand while being drawn into a whirlpool of power named “world”.

(Source: wikipedia)

Nine Songs of the Moving Heavens is the prequel to Qin's Moon (The Legend of Qin). Although the two animations have intersections of characters and their timelines, Nine Songs of the Moving Heavens is an independent story. (Source: edited from wikipedia)