As with One Piece, Amazon is doing this to boost the morale of kids (and also grown-up fans) staying home to help prevent the spread of coronavirus.
With the coronavirus outbreak an ongoing situation in Japan, the country has indirectly been told to stay home as much as possible.
Both the One Piece chapters and Pokémon episodes will be free until April 5, and if that’s somehow still not quite enough to keep you occupied, don’t forget that there are 450 volumes from other manga series going free-to-read too.
On the other hand, if you’re more of an anime fan, you’ll be happy to know that Amazon Japan is making a huge chunk of the Pokémon anime free-to-watch.