/cgl/ - Cosplay & EGL

Not sure if I should ask here or on /fa/. It's about Japanese streetwear so I guess it sorta belongs here. How do I pull off the Japanese oversized look? The reason I can't ask /fa/ is because the oversized look is way more exaggerated in Japan. In the west, it's a more subtle look. I know in the west, you buy an oversized cut in your own size, so if you're a medium, you buy an oversized medium shirt. Generally you're not supposed to just size up from medium to XL because it's going to look ill fitting, like you don't know your proper size. But that's western oversizing conventions though, which is not what I want.

So what are these Japanese people doing exactly? Is it like the west where if someone is a size medium, they just buy an outfit meant to look oversized in a size medium, except Japan just makes their oversized medium look fuck huge. Or are these people going against western conventions and sizing up three to four sizes and wearing like XXXL tees? Should I buy tees and hoodies made in Japan and made specifically for the purpose of achieving this look or can I just buy XXXL stuff in America and achieve the same look?