Romani Ranch is a location in The Legend of Zelda: Majora's Mask. If you leave the South Gate but break right instead of heading towards Woodfall, you'll arrive at Romani Ranch, equivalent to Lon Lon Ranch from The Legend of Zelda: Ocarina of Time. The entrance road is blocked by a large boulder and requires a powder keg in order to be destroyed.
Since her sister doesn't believe her, Romani asks you to help her fend off the "aliens" that come to take their cattle. If you don't fend off the cattle and return to the Ranch, then you'll see Cremina crying about how she should have believed Romani about the "aliens".