It is impossible to determine whether there are any fake Omega watches purchased on behalf of Japan, because it depends on the reputation of the purchaser and the source of the watch.

If the watch was purchased through an official channel, such as an authorized Omega dealer or boutique in Japan, then it can be guaranteed to be authentic. However, if it is purchased from an unofficial channel, there is a possibility of a counterfeit product.

If the watch purchased is indeed genuine, it can be repaired and maintained within China through OMEGA's official after-sales service. In China, Omega owners can use the red warranty card to enjoy warranty service at Swatch Group after-sales service departments worldwide.

Please note that in some cases, especially when purchasing so-called "parallel imports" outside of China, after-sales service may be denied. This is because after-sales service centers in China sometimes refuse to provide warranty for watches purchased outside of China for various reasons. In this case, if the watch was purchased from an officially authorized channel, you can try to repair it through an official after-sales service center, but if the warranty is denied, you can also consider repairing it through some independent watch repairers.

Finally, for those who buy Omega watches, the likelihood of a malfunction within the one-year warranty period is extremely low. If a malfunction occurs within the one-year warranty period, Omega is easy to repair at an acceptable price.