The previously announced 10th anniversary “celebration animation” for The Idolmaster Cinderella Girls, titled Eternity Memories, has been released on the Idolmaster YouTube channel. The anime has a length of 50 minutes and features appearances from dozens of characters.

The celebration animation is directed, storyboarded, and written by Hideki Kagamachi, who previously directed several anime commercials for the The Idolmaster: Cinderella Girls Starlight Stage game. 

Other staff include Norie Igawa (“Mr. Fixer” music video) as character designer, Ayumi Satou (That Time I Got Reincarnated As A Slime) as art director, Stella Road’s Naomi Nakano (Shine Post) as color designer, and Kentaro Kashiwagi (Tribe Nine) as photography director. Cygames Pictures is the animation production company.

The Idolmaster Cinderella Girls is a free-to-play mobile social simulation game that was released in 2011. Service is set to end on March 30, 2023.

A two-season anime adaptation spanning a total of 26 episodes premiered in 2015. An OVA was released afterwards in 2016. Other anime include 2017’s The Idolmaster Cinderella Girls Theater short anime and the 2018 Spin-Off anniversary animation.

Crunchyroll describes the main anime series as:

There are many idols with long-established talent agency 346 Production. And now the company is starting a new program, the Cinderella Project! Girls leading normal lives… They are chosen to be aspiring idols and see another world for the first time in this Cinderella story. Can they all climb the stairs that lead to the palace? The magic begins now…

Bandai Namco Entertainment’s The Idolmaster (stylized as THE iDOLM@STER) multimedia franchise begin with a 2005 arcade game that was ported to the Xbox 360 in 2007. It has since spawned multiple games and anime, with the latter including series like 2007’s Idolmaster: Xenoglossia, 2011’s The Idolmaster, 2015’s The Idolmaster Cinderella Girls, and 2017’s The Idolmaster SideM. The franchise has also inspired radio shows, drama CDs, soundtrack releases, and print media.

Source: Idolmaster YouTube channel