Japan independently developed many of the qualities required for success in science and technology. Many other cultures are rapidly acquiring science and technology. The West was first, not unique. To explain the success of the West in science and technology, we need to identify and focus on the cultural conditioning that was most distinctive to the West.
Crucial attributes are likely also to show up in the cultural conditioning of Japan.
Sooner or later change will happen, even if the society stays isolated. Pre-contact Hawaii, other isolated tribal societies. Easter Island, about as isolated as a society can get, collapsed from internal warfare and environmental destruction before Europeans arrived. Sooner or later a change too powerful to exclude is bound to happen. Sooner or later a change agent will probably appear that is too powerful or too resistant to assimilate.