No, it's a mockumentary based on the Tachiguishi from Mamoru Oshii's Kerberos saga. Although many people confuse it as telling some subversive take on Japanese culture this is not exactly the case.
Yes it is the fourth film in the Kerberos Saga. It is part of a side project focusing on the Tachiguishi who are legendary fast food eaters in that world. There are two live action shorts also released that focus on these characters.
