I use Buyee to shop on Mercari Japan, and have ordered many items with them. The fees may add up, but they often have coupons to exclude the service fee, which is really nice! I've tried two different ways of shipping, the time can vary depending on your country's policies when it comes to packages, so be aware it can take time to get to you (DHL is super fast, but a little pricey). All packages I've gotten were intact with zero damage. Their customer service provides quick responses and is easy to communicate with! Buyee also doesn't include sold out items when you search on Mercari, so you don't have to be disappointed when you click on an item that's not available anymore.