This is a tool-assisted speedrun. For more information, see http://tasvideos.org/3796M.html. TAS originally published on 2018-09-30.
Rockman & Forte: Mirai Kara no Chousensha (commonly translated as Mega Man & Bass: Challenger of the Future) is a sequel to Rockman & Forte (Mega Man & Bass), published by Bandai exclusively for the WonderSwan. A version of Rockman from the future - calling himself R-Shadow this time - travels back in time again with a group of robots to wreak havoc, until either Rockman or Forte put them all down.
In this movie, Mothrayas (http://tasvideos.org/Mothrayas.html) beats the game with Forte (Bass) in record time.
We also have a movie (http://tasvideos.org/3199M.html) that beats the game with Rockman (Mega Man).