Yes, Japanese society is bound by rules. But the rules are many, complex, and often obscure, and ordinary Japanese are expected to infer many of them. What's worse, one of the biggest overarching rules is "it is better to preserve social harmony and/or not risk embarrassment than to engage in honest discussion". Which means compared to Westerners, Japanese people rarely talk about their true feelings. Which means the feelings of everyone around you, the very basis of your social status which itself determines which book of rules you apply, must also be inferred.

This makes ordinary life a considerable struggle for socially deficient people. The much greater difficulty finding your social bearings in Japanese society and successfully putting on an appropriate performance may itself explain why otaku and hikikomori are such a huge phenomenon in Japan. In fact the 80s, when fans met at cons and such, they would always address each other in the most formal terms possible -- with the polite pronoun "otaku" -- to avoid offense, because it was difficult to see where the dividing lines were to stop being so formal. But this behavior was still considered weird and idiosyncratic enough among mainstream Japanese to give them the distinct name of "otaku".

Japan is lovely, but being Japanese is hard.