Despair Disease

Despair disease is a disease introduced in Danganronpa 2. It's a disease that is found on the island. It is explained by Monokuma that there are insects that transmit the disease.

In-game
In chapter 3, the students meet up at the restaurant as instructed by Monokuma, while Akane is still sad about Nekumaru's "death". Eventually, Hajime notices that Nagito is acting strange, such as stating that Fuyuhiko was cloned after his injury. Eventually, when Ibuki turns up, everyone notices that she is acting unusually casual. Moments later, Monokuma explains that she contracted Despair disease. He also admits that he placed them overnight. He says that it's a "Reaaaally annoying disease where you get a high fever, along with various other symptoms that are full of despair!".

Trivia

 * The symptoms appear to differ based on the person, as stated by Monokuma.
 * Nagito, Ibuki, and Akane are the only people who contracted the disease.
 * There appears to be different versions of the disease. For example: Akane has the Coward disease, Nagito has the Liar disease, and Ibuki has the Gullible disease.
 * It also appears to be contagious, as it can transmitted the same way as the common cold.
 * It also increases the infected person's urge of dying, or murdering others.
 * There is also no cure, as stated by Monokuma.