Eiichiro Oda Before One Piece (manga)

In the short story "Monsters!", the main character's name is Samurai Ryuma. This is the same Ryuma (confirmed by Oda) that shows up as a zombie in the Thriller Bark arc of One Piece. "Monsters!" is in fact part of the One Piece world, just like Romance Dawn.

In Ikki Yako, a civilian is seen with a Nightmare Before Christmas shirt.

"God's Gift for the Future" was the first time Oda's joke characters Domo-kun and Nnke-kun appeared.

The following one-shot manga were published in the following years: Wanted - 1992, God's Gift for the Future & Ikki Yako - 1993, Monsters! - 1994, & Romance Dawn Version 2 - 1996.

Spiel the Hexagon remains to date, the only One Piece villain who could use "magic" in this context. All other powers in the actual One Piece storyline are the result of skills such as Haki, technology such as the cyborgs or Devil Fruit powers.

Unlike Galley in the Romance Dawn version 1, Spiel hasn't made a pysical appearance in the anime.

It was never truly explained why Spiel needed Balloon's magical blood or what purpose it would served him.

"Spiel" is the german word for "game".

In the official One Piece storyline, it was stated that had Portgas D. Ace been born a girl, he would have been Ann the same name as the girl Luffy encounters in Romance Dawn Version 2.

The title page of One Piece Chapter 8, features birds that look like Balloon in Romance Dawn Version 2.

In the One Piece manga, there is a scene wherein Luffy accidentally gets himself caught by a giant bird. The way the bird caught Luffy in it's beak is similar to the way Balloon transported Luffy back to Ann.

Ann resembles Nami from the Official One Piece series. Both Ann & Silk(from Romance Dawn Version 1) were both Oda-san's attempts in creating a female character for his series. Unlike Silk, there was no signs of Ann joining Luffy's quest. Her backstory was farther from Silk's & Nami's backstory with no indication of having a parent or legal guardian.

Although the currency is not the same as Berries, Gill Bastar's bounty is the highest known in all of Oda-san's works based on numerical value. At Z 970,000,000.

The special notebook's concept in "God's Gift for the Future" is similar to the Death Note from the series with the same name. It is a notebook belonging to a shinigami that will kill the people who have their names written into it.

If you look closely in "Monsters", there is a man with scar and face exactly like Guko from "Ikki Yako" right when D.R. is introduced.

Bran & Ryuma look excatly like Roronoa Zoro, except with a different hair cut and outfit.