Whenever I hear “top-down” or “vertical” society, I recall Gatchaman Crowds. In that series, Rui Ninomiya references Japanese anthropologist Chie Nakane and her 1970 book Japanese Society, stating that one of their goals is to destroy vertical social structure still prevalent in modern Japan.
The basics of vertical society are just as it sounds: a top-down hierarchy with a “senior” and a “junior,” but Nakane reinforces that these titles and ideas are all tied into the group with which the person identifies. A Japanese person will first compare or establish themselves in a group, then branch out into their given profession or role.
For example, she states that asking a Japanese engineer about their job would result in that person saying, “I’m from A company” rather than the more western response, “I’m an engineer.”
Made in Abyss is a vertical society in both in social construction and physical existence.
There’s an obvious, “It works on two levels!” joke here, and both societal and physical structures are reinforced visually. This only adds to the post-apocalyptic feel of the series, dropping clues as to what may have happened in the past to create such a vibrant society that is seemingly on a dangerous precipice.