Kiseichuu no Ichiya

Trippy, surreal, dark and macabre. If you like Cat Soup you'll probably enjoy this short. 

Both are old, short movies with almost no story and hand-drawn like animation. Both are dementia genre, so you will feel like you´re on a drug trip while watching those. Also, both have no dialogue. 

Cycle. I'll admit that this is quite the odd connection, but the cyclical nature of the two do share some vast similarities. This idea that there is no ending to what has started, these iterations are seemingly endless, and the means to break this odd loop that is life itself. AOT does this with more background and lore to it than the honest plain work of Yoji Kuri's Midnight Parasites. It's a fine relation for going around the different ways one can present some philosophical order bestowed for the human mind to think of. One's a full series compared to a shorter mini-movie. I'd recommend starting from the beginning of AOT as well. Also, both anime have weird people eating other people. read more 

An unearthly presence of extraterrestrial beings. They arise, perform the abnormal, radiate repugnant fumes to the average viewer. Despite this, a lot goes deep beneath. Drawing closer to the core, you will find, interesting messages and themes to reflect on. An impressive feat. 

Both are old short anime mady by Kuri Yoji. Both have no story and are just completly random or even surreal. Watching these may be a bit trippy. While Kiseichuu no Ichiya is completly animated, The Bathroom have some live action parts. 

Both are short, 10 minutes long movie. Both are surreal, trippy and mindfucking and underrated. Both were made by same director and both are pre-1980 anime.