On September 21, 2021, director Nobuya Narita and composer Raito confirmed on Twitter that the "next" installment of Under Night In-Birth was in development. Narita expressed interest in the announcement of said title coinciding with the tenth anniversary of the original release of the game. It was not explicitly stated whether this referred to a new version of Under Night In-Birth or a wholly new title set within the same universe.[24][25] Eventually during Evolution Championship Series on August 4, 2023, the title was announced to be a sequel titled Under Night In-Birth II [Sys:Celes] and it was released on January 25, 2024. It serves as a final chapter of the series.[26] It features DLC characters in season passes.[27] During Paris Games Week 2023, an open beta test for [Sys:Celes] was announced to take place from November 17 to 20, 2023 for PlayStation 4 and PlayStation 5.[28] An early access release was made available for PlayStation owners in Japan, Hong Kong, England and the United States on January 21, 2024. After Stormy Night tournament in November 2, 2024, an arcade version for Sega's ALLS was announced. It is be powered by ALL.Net P-ras Multi version 3 and is set to be released on March 27, 2025, in addition to the first two DLC characters will be available at launch, while the remaining DLC characters will be added post-launch at a same day as their DLC console releases.