(traditional) cwTeX Q Yuan
cwTeX Q Yuan (中圓體) is a free rounded traditional Chinese font that you can download for free. cwTeX fonts were created by Tsong-Min Wu and Tsong-Huey Wu under the GNU General Public License Version 2 or later. And in 2014, the fonts was released under Open Font License, which means you can use this font for commercial purposes.
Free for personal and commercial use.
Once landed on the Google Drive, you will see 4 files. Click on the bottom link (which is the latest version) to start the download. It includes all 5 different fonts from cwTeX.