Soukoku

Soukoku is the slash ship between Nakahara Chuuya and Dazai Osamu from the Bungo Stray Dogs fandom.

Canon
Both Dazai and Chuuya were paired up with each other when they were 15 years old. The man who had paired them was none other than, Mori Ougai; the new chef of the mafia, reasoning that "Only diamonds can be polished by diamonds". The duo was named Soukoku after one memorable night during the event of "Dragon head's rush", where they had defeated an enemy organization over night. Resulting them to recognize themselves as Soukoku or Double Black among other enemy organizations by Mori Ougai. They are also known as "Yokohama's vicious duo". The pair as well as have unconditional trust upon each other. As stated in Bungou Stray Dogs: Dead Apple guide book "The core characterization of Dazai and Chuuya's partnership is based on pure trust where both of them are capable of leaving each other's life on the other's hand without a second thought or doubt." (Pg 54-55). Their partnership were collapsed for 4 years when Dazai Osamu decided to leave Port Mafia and join Armed Detective Agency. However, their partnership, once again had resumed during the event of a foreign organization, named The Guild. As well as the duo seem to be know each other to a questionable point when Dazai Osamu said he knew Nakahara Chuuya's "Thrust" to which Nakahara Chuuya had responded with "I was just going easy on you" and an extremely flustered face. That being said, Dazai Osamu once desired to witness the nudity of Nakahara Chuuya in Bungou Stray Dogs Wan. The duo also competes against one another as can be seen in Wan where they are found in a competition against each other for who can eat more ramen. Adding onto it, in Chapter 20 of Wan he even dressed up as a dog to catch Chuuya's attention despite his disheartening for dogs. Following the event, he once also dressed up as an old lady who could not walk properly and made Nakahara Chuuya carry him to the other side of the rode. Dazai Osamu also have a record for climbing up to Nakahara Chuuya's office just to give him a cup of coffee, simply reasoning it as "My partner worked hard so I came to give him a cup of coffee."

Fanon
It is believed that Soukoku is a business ship since it earns and buys a lot, however, many disagrees as well. It is also believed that, their name of the partnership was supposed to be "Double Shades of Black" but was changed to Double Black.

Trivia

 * During the character designs, the creators of the series mentioned that Dazai Osamu and Nakahara Chuuya would be in a Partner/relationship as well as Nakahara Chuuya was originally designed for Dazai Osamu.
 * The ship is the most popular ship among the Japanese and Western fandom
 * Their stage actors ships them (Dazai Osamu played by Hideya Tawada and Nakahara Chuuya played by Ueda Keisuke.
 * The sentence used to introduce the Double Black episode was "The head may err, but never the blood." (Showing the depth of their relationship as something magnetic and rather deep.)
 * Dazai Osamu is 51 days younger than Nakahara Chuuya
 * They express their emotions towards one another as "I hate you". However, they also get very worried when the other is hurt, as well as very proud when the other accomplishes something. (refer to ep 9 season 2)
 * They have a lot of sexual tension within them (Nakahara Chuuya once pulled Dazai Osamu by his hair in episode 10 from season 1
 * Their height difference is 21 cm (Nakahara Chuuya- 160 cm, Dazai Osamu- 181 cm)
 * They have a whole episode dedicated to them for their reunion in season two, called "Double Black"
 * Nakahara Chuuya has put his life on the line just to save Dazai Osamu for quite some times.
 * Dazai Osamu, despite his hateard for Nakahara Chuuya's hat and clothing, still folded them and wiped his blood off his face in ep 21 from season 2
 * During one of the twitter events Nakahara Chuuya confessed that he was, indeed in an inseparable relationship with Dazai Osamu. 23621625 1736650933306568 8488735499124480906 n.jpg
 * Nakahara Chuuya gently watching over Dazai Osamu proof .jpgara Chuuya gently Watching over Dazai Osamu Proof.
 * [[File:5b71a19e6e45cc82369a0a5fd5efe978--bungou-stray-dogs-dazai-chuuya-chuya-nakahara.jpg|thumb|315x315px|Dazai Hugging Chuuya]]Dazai Osamu stated that he did not enjoy the company of men or hugging men. Yet he was seen hugging Nakahara Chuuya from the side while wearing a very amused smile as well as winking at the other man.
 * Tumblr messaging ovp07ruvOE1qj7xgl 1280.jpgara Chuuya and Osamu Dazai on a night date on the 14th of March (White Day) at the very popular night date park in Yokohama.
 * DaFzzRpU0AEOFZJ.jpg Promo Visual for the movie "Bungou Stray Dogs, Dead Apple" (On each other's chest)
 * DPIO9FiUEAIeRQT (1).jpgtmas eve date at the Red Brick's market in Yokohama. (A place where one usually does not visit alone, rather visits with someone who they are in a relationship with.)
 * 2fe0d8782432444a617cef50ba4a7257.pngtmas Date 2016
 * DXUs7CzUQAAKt 7.jpg"The Bandage is a heart"
 * DX18EW2U8AAlXfq.jpgara Chuuya worried for Dazai Osamu's well being.
 * DbiWmWxVQAAoPSy.jpg faces of a happy couple.
 * Red camellias (Camellia Japonica) are often used to represent them. The said flower stands for love, passion, trust and desire. Some cases it also represents death or sorrow of losing someone and is related to Nakahara Chuuya's ability (For the Tainted Sorrow) where he has a higher chance of dying.
 * Dazai Osamu, Similarly to Mori Ougai had also paired Nakajima Atsushi and Ryunosuke Akutagawa as "New Double Black" or "Shin Soukoku" where Shin Soukoku reflects more if not less of Soukoku.
 * The name was canonically given to the pair of men from the boss of mafia, Mori Ougai.