The full title is Dangan Ronpa: Academy of Hope and High School Students of Despair. However, do to the length, fans all over the world (and on Pixiv) shorten it to Dangan Ronpa. The shortened name has caught on.
A sequel was recently announced, called Super Dangan Ronpa 2: Goodbye, High School of Despair. (The tag for it is スーパーダンガンロンパ2). This has an independent Pixpedia article over at スーパーダンガンロンパ2.