Eiichiro Oda is the genius mangaka who has written one of the greatest works of fiction in One Piece. The manga began serializing in 1997, and since then, it has gone on to shatter numerous records, even becoming the best-selling manga series of all time. One Piece crossed the 500 million mark a while back, and it is not showing any signs of stopping. While there is no denying Oda's Magnum Opus is One Piece, the author worked on other projects before starting work on the bestseller. One of Oda's most notable projects is MONSTERS, which received an anime adaptation only recently. However, there is a big reason why it took so long.