The sanctions won't make a difference and Japan will get a free pass.
The Chinese will smuggle stuff in via third or fourth parties or outsource to chipmakers in other countries. And as the ban is political, the Chinese government will fork out the extra cash to ensure supply. Japan usually gets a free pass from Washington to dodge sanctions required of other vassals as they would function as a US aircraft carrier/giant airbag in any Pacific Rim conflict. China couldn't hit the US but it would cheerfully hit Japan and the US airbases there. But having your bento and eating it is getting harder as Cold War 2 kicks in. Japanese companies are still partnering with Russian energy projects and would like to keep importing Russian timber (which the construction industry relies on). Chinese tourists were a huge source of revenue pre-pandemic, and Tokyo was hoping that they would soon return post-Covid Zero en masse. Despite any political rhetoric, they would like to stay on economically amicable terms with the CCP. It's likely that Japan will still get a free pass denied US companies and European vassal states, but they will have to keep a lid on it or others will be jealous.