I read something a few months back, and apparently forgot to add it to any lists. It was a Future set, and most of the story was focused on a giant storage facility where they stored the brains of the "dead" in tanks. Story focus's on the workers lives, as they clean the tanks, what they do, and the secrets behind the building etc.

spirit circle that story is one of the past lifes (or future life) of the mc

[img]http://www.nodiatis.com/pub/10.jpg[/img]

That would be spirit circle. It has a bunch of stories about the main characters previous lives(though this brain tank one is the future). Anyway, it's like the 5 story in or something.

https://www.mangaupdates.com/series.html?id=78322

thats it, thanks!!