Spike Chunsoft recently announced that the Danganronpa 3 anime will have two seasons, with the second season serving as a prequel to Danganronpa 2: Goodbye Despair.
The first season, titled Future Volume, takes place after the events of the second game and will follow the surviving members from the first Danganronpa game alongside 12 brand new characters to the series. The second season, titled Despair Volume, will take place before the events of the second game and will follow its entire cast which you can view above.
The first season is due to air sometime this July.