Where can one buy Manga locally in Australia?
Many bookstores, such as Dymocks, also sell manga, and have online stores where the manga in stock. You may also want to check Kinokuniya, since they do imports from Japan as well as stocking locally distributed books. Of course the Japanese imports are typically in Japanese, but there are some rare bilingual releases if you're able to find them.

Additionally, it looks like Simon &amp; Schuster has picked up the rights to distribute Viz Media titles in the wake of Madman's announcement, so most of those should still be available after May. The other companies, though, might be a bit trickier to track down. Looking at the S&amp;S website, they mainly redirect you to retailers rather than selling directly, but hopefully it won't be long before the manga shows up on their site so you at least know where to get them.