According an interview of Oda in July 22, 2014 with the author of the series “Chibi Maruko-chan” -Momoko Sakura

Oda: Yes, I already decided on how it’s going to end. Should I tell you now?

Sakura: …. Well, I want to know, but I probably shouldn’t. BUT, the One Piece, it’s not something like “the growth your heart went through”, right?

Oda: Hahaha, no no, I won’t be pulling off some kind of Wizard of Oz thing like that. After having gone through an adventure like that, it wouldn’t be fair to not actually give them a reward.

So I guess now we can all rest assured that the One Piece ISN’T “a dream”, or “the bonds created among the straw hat crew” etc.

now oda has use many mythology and story from various culture to incorporate in one piece considering that i thought might have use some japanese myth for the real deal one piece

And i found this

Tide Jewels kanju manju
Tide jewels
In Japanese mythology, the tide jewels– individually, the kanju (干珠, lit. “(tide-)ebbing jewel”) and manju (満珠, lit. “(tide-)flowing jewel”)– were magical gems that the Sea God used to control the tides. Classical Japanese history texts record an ancient myth that the ocean kami Watatsumi 海神 “sea god” or Ryūjin 龍神 “dragon god” presented the kanju and manju to his demigod son-in-law Hoori, and a later legend that Empress Jingū used the tide jewels to conquer Korea.
Tide jewels interrelate Japanese dragons and wani sea-monsters, Indonesian mythology, the nyoi-ju 如意珠 “cintamani; wish-fulfilling jewel” in Japanese Buddhism, magic jewels of Nāga kings in Hindu mythology, and the pearl associations of Chinese dragons in Chinese mythology 
The Japanese compounds kanju 干珠 lit. “ebb jewel” and manju 満珠 lit. “flow jewel” combine kan 干 (cf. 乾) “dry up; drain off; ebb (tides); recede; oppose” and man 満 “fill; full; rise (tides); fulfill; satisfy” with ju, shu, or tama 珠 “gem; jewel; precious stone; pearl; bead”. Compare the reversible compounds kanman 干満 and mankan 満干 or michihi 満ち干 meaning “ebb and flow; high and low tides; the tides”. Shiomitsu-tama 潮満珠 and shiohiru-tama 潮干珠 are archaic “tide jewel” names using shio or chō 潮 “tide; flow; salt water”. 
Early references
Two Nara period (710-794 CE) historical texts record myths that the Sea God presented the kanju and manju to Hoori, and a Kamakura period (1192-1333 CE) text says the legendary Empress Jingū used the tide jewels to conquer a Korean kingdom in 200 CE.
The tide jewels
are central to “The Lost Fishhook” legend about the fisherman Hoderi and hunter Hoori, two brothers who argued over replacing a lost fishhook. Hoori went searching to the bottom of the sea, where he met and married Toyotama-hime, the daughter of the dragon Sea God. After living three years in the undersea Ryūgū-jō 竜宮城 “dragon palace castle”, Ryūjin presented Hoori with his brother’s fishhook and the tide jewels, and arranged for him to take his sea-dragon bride back to land. 
The ca. 680 CE Kojiki 古事記 “Record of Ancient Matters” uses the archaic names shiomitsu-tama 潮満珠 “tide-flowing jewel” and shiohiru-tama 潮干珠 “tide-ebbing jewel” in two consecutive passages.
The first describes the sea-god’s advice to Hoori about how to confront his duplicitous brother Hoderi. 
The ca. 720 CE Nihon shoki 日本書紀 “Chronicles of Japan” or Nihongi日本紀 has several references to tide jewels.
….. Empress Jingū found a Buddhist nyoi-ju 如意珠 lit. “as-one-wishes jewel”, 
The ca. 1195 CE Mizukagami 水鏡 “Water Mirror”, which is a collection of historical tales, confabulates the Nihongi legends about the tide jewels and Jingū conquering the Koreans (Bassett 1885:74). This text uses some different names, Sāgara 沙竭羅 (one of the 8 Dragon Kings) for the Sea God, and Koryo 句麗 or Koma 蓋馬 for the Korean kingdom Goguryeo. 
Simple Explanation :
These two jewels have opposite effect like yin and yang are part of same bodyKanju – ebb jewel it has ability to recede ,dry ,pull back or drain a tideManju – flowing jewel it has ability to raise the tidesGist from the Nihongi “Chronicles of Japan”
Legend says that the Empress of Japan, Jingu, once decided to take over Korea. To help her in her conquest, she sent one of her servants into the nether realms to talk to the Dragon King. She wanted the tide jewels, two relics forged by the Dragon King, which controlled the very seas themselves. He granted the Empress’s request and, with the aid of the relics, they took over Korea. When the invasion was over, she cast the jewels back into the sea, returning them to the Dragon King.
These jewels are have opposite force and stable only when they together
like yin and yang
[​IMG]and in scientific terms like the two poles of magnet[​IMG]

this bring us to next part

Mystery of Grandline

The Grand Line is the ocean current that is surrounded by the Calm Belts and follows an imaginary line that runs from north-west to south-east across the middle of the world and perpendicular to the Red Line. The Red Line is a vast continent that circles the globe from north-east to south-west. These two lines divide the rest of the Blue Sea into the Blues: North Blue, East Blue, West Blue, and South Blue


Now what happens when we bring the two opposites pole of magnets in close proximity

According to my theory kanju and manju are like opposite poles of magnets kept at a distance but as they very power full they create a very strong magnetic field

leading to creation grandline


Normal compasses do not work on the Grand Line because of the nature of its magnetic fields. In order to navigate the Grand Line, a special compass called a ‘Log Pose‘ must be used. The Log Pose works by locking on to one island’s magnetic field and then locking on to another island’s magnetic field.

due to presence of kanju and manju on the opposite sides of grandline magnetic field is created effecting the islands in it

  • and their power leads to constant chaos in ocean of grandline
  • rise and fall of waves
  • chaotic climate in grandline
  • this strong force which created grandline also lead to of clam belt as force was so strong in grandline
  • leading to lack of winds and tides in clam belt

Location of kanju and manju in one piece universe


Yes they are Raftel and Mariejois

As u can see Reverse Mountain are opposite to Mariejois
If we see Earth as a giant magnet it’ll like


why Mariejois u say One Piece was treasure of Ancient Kingdom which World Government stole in Void Century atlest a part of it
that’s why World Government is so afraid of mention of One Piece bcoz they afraid its true power
Whitebeard aslo mentions it in Marineford

Doffy also mention a treasure in Mariejois although many people think its Uranus i dont think so
Doffy understood its power but not to full extent

Now Joy Boy in Void Century hide the other part of treasure and hide it Raftel and created the grandline so that world government couldn’t have their hands on it

Roger’s Failure

One who obtains One Piece will have power over sea and ocean and will able to control of all ocean the Pirate King

Roger conquers the Grand Line and reached Raftel and obtained other part of treasure and named it One Piece
Now what makes different from other Yonkos is not because he had more military might or not because he finished journey to Grand Line

its because he held power equivalent to World Government
World Government held who one part of treasure symbolizes justice
and Roger held other part of treasure symbolizes injustice -pirate king

Why did Roger failed and disbanded is group ?

  • as much as powerful Roger Pirates were they at least 1 ancient weapon and one piece
  • roger lacked one thing that luffy has ability to make allies
  • according to me a part will of D also is to unite the old nakama/allies
  • unable to fullfill promise to mermaid princess
  • roger knew he wasnt the one who will bring down the world Government
  • hence he disbanded his crew and got captured to pass along the message to his successor

Conclusion :what will happen if two pieces are brought together ?

  • the grandline will disappear
  • weather and sea will return to its original form
  • and clam belt will disappear too
  • and luffy will be king of all of sea

Thanks to those who read till the end
Hope you like

*Theory by D kar