Here is my summary for Ace novel in ONE PIECE Magazine Volume 1. The novel is pretty long, so I'm worried that summarizing it in English may be beyond my ability..
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A guy has been eager to write an adventure essay like "Brag Men" (seen in Ohara). He is now incapable of escaping from a too beautiful desert island called "SIXIS" located in East Blue.
The current around the island is pretty irregular that nobody can escape.
When he is talking to a skeleton next to him, he finds that someone else joining the conversation without realizing it. This is the first moment when "he" and Ace talk.
Ace says politely, "Nice to meet you." The man thinks Ace is about the same age as him.
He considers Ace comes to the island to rescue him, but the fact is that Ace is also a victim due to his ship wrecked.
The man is annoyed that Ace is smiling cheerfully in spite of this predicaments.
The man has spent 3 days on the island, whereas Ace 6 days. Ace says, "How about creating a raft with me?"
Both Ace and the guy are seeking for a treasure which is said to be hidden in the island.
Ace keep asking the man about his name, but the man doesn't want to tell him about it since he has already thrown away his own name on the day he set out to ocean.
Ace says, "We are already friends, right?" (exactly the same words when Luffy invited Usopp to Going Merry). The man tries introducing his pen name as "Ace" borrowing Ace's name,
but Ace prevents and suggests him to make his pen name Deuce since he thinks the pronunciations are similar.
The man doesn't feel bad since the meaning of Deuce being "bad luck" fits into his current situation.
Ace decides to call him "Masked Deuce" since the guy wears a mask so that Marine don't notice his face.
Deuce was a medical student with bad grades. His parents are indifferent to him. He just wants to have an adventure and doesn't want to be a wanted man.
Ace and Deuce talk about their family. Ace mentions Luffy in the talk with smile. Deuce happens to say, "If someone's father were Roger, I'm sure he'd rather die."
Ace suddenly becomes quiet and shows a very serious facial expressions, which makes Deuce realize that Ace is the real son of Pirate King.
Deuce walks off with mixed feelings, telling Ace not to talk to him anymore.
Several days passes. Ace fails to escape from the island with his ship wrecked. "I can't die in such a place...!"
He is not in a positive mood anymore. Deuce tries to find food and water, but in vain.
One day, Deuce finds Ace grabbing a large fruit in his hand on a beach.
Deuce is hungry and comes to the conclusion that there is no problem even if he kills Ace since Ace is a son of a legendary criminal.
Right before he attacks Ace with a tree branch, Deuce's stomach growls. Ace notices him and considers that Deuce comes to help him make a boat.
Ace offers him to eat the fruit, but Deuce rejects it due to the feeling of guilty for trying to kill him.
Deuce finally realizes that Ace is a nice person despite him being the son of Pirate King. As a result, they decide to share the fruit.
Deuce feels it is the most terrible -but delicious at the same time- food that he has ever eaten. Deuce turns around and finds Ace burning!
Both of them are surprised at Ace's burning body. The fruit they ate is Mera Mera no mi.
After several days, Ace is capable of controlling his fire. Deuce calls the ship "Striker" which moves forward by rotating plates with the help of fire.
Deuce says it was a fake rumor that a treasure is hidden in the island. Ace answers with a smile, "Not sure.."
Ace reaches his hand toward Deuce and says, "You'll come with me, right?" Deuce replies, "I can write a good adventure essay with you."
They shake hands tightly. Ace declares, "I'm gonna go beyond Pirate King!" Thus, Spade Pirates was born.