While primarily occurs at Big Adventures Park, a few locations, including Cloud Island, can be discovered beyond the original area.
Unfortunately, significant progress must be made with the main storyline and the residents to unlock any of these additional areas.
On Cloud Island, plenty of new things await, such as two new friends, new clothing and furniture, new recipes, and an entirely new appliance.
While Merry Meadow is somewhat easier to reach and unlock, Cloud Island, unfortunately, requires that all the different parts of the main island be restored, and even then, some friendship levels and quests must be unlocked as well.
While playing through, you should come to realize relatively quickly that one of the biggest goals on the island is to help Hello Kitty and the other Sanrio characters restore the different areas of it.