danganronpa 2.5: nagito komaeda and the world vanquisher
Danganronpa OVA included with the Japanese limited edition of Danganronpa V3: Killing Harmony. It regards Komaeda Nagito and his "ordinary" life, which soon gets turned upside down by an entity only known as "The World Destroyer".
Set between Danganronpa 2: Goodbye Despair and Danganronpa 3.