A growing number of trailers and preview episodes of new anime have been released as ONA.
ONAs have the tendency to be shorter than traditional anime titles, sometimes running only a few minutes.
[3] There are many examples of an original net animation, such as Hetalia: Axis Powers, which only last a few minutes per episode.
But while that was true for the beginning of the 2010s, this began to change in the second half of the decade as full series began to be licensed exclusively for streaming services like Netflix, Amazon Prime Video, and Disney+.
[5] Early examples of ONA series include Infinite Ryvius: Illusion (2000),[6] Ajimu (2001),[7] and Mahou Yuugi (2001).