'Deep Blue Course') is a side-scrolling shoot 'em up video game created by Chinese developers Shanghai Manjuu and Xiamen Yongshi, released in 2017 for the iOS and Android operating systems.

A two-episode original video animation adaptation of the Azur Lane Queen's Orders manga was released in July 2023.

Players must navigate optimally and assemble their fleets tactically, to clear obstructing enemies and, using minimal movements, reach the map's boss.

When the player moves their fleet across the map, they can be ambushed in random encounters from which they may take damage, or they can be forced to engage the enemy, using fuel and ammo.

[7] When battling an enemy, players can use a virtual joystick to control the front row, which can automatically fire shells at targets and manually launch torpedoes.

Players may increase Dormitory character capacity, unlock a second floor which recovers morale, and buy special interactive furniture using the in-game currency.

[16] The start of the game features an anthropomorphic recreation of the Battle of the Denmark Strait, where the personification of famed British battlecruiser HMS Hood is sunk by characters representing the German forces.

The rest of the game's main plot partially follows the United States naval engagements in the Pacific War.

An early version of the game featured a combat system of a five-character fleet in a single or double column line of battle.

[17] The developers sought to further differentiate the game by featuring characters based on preserved museum ships from earlier times, such as the pre-dreadnought battleship Mikasa of World War I, which was served as a flagship during the Russo-Japanese war, and the Russian protected cruiser Aurora, the ship famed for its October Revolution involvement.

[26] Li Hengda, president of Yostar Inc., revealed that although he saw Azur Lane's potential, he did not expect the level of popularity the game experienced in Japan.

Through Azur Lane, Yostar established contact with distinguished Japanese enterprises and creators and was met with welcoming responses.

[27] In March 2018, Korean players accused Nardack, a guest illustrator in their regional server, of being radical feminist and alleged that she is "Megalia".

[28][29] A special program featuring voice actress Yui Ishikawa visiting the office of one of developers, Manjuu Ltd., in Shanghai was aired on the Japanese streaming television platform AbemaTV in May 2018.

[30] However, misuse during the program of the trademarked term "kanmusu" (艦娘) to refer to the game's personified warship characters led to Yostar being publicly warned by DMM.com, publisher of Kantai Collection.

Yostar issued an apology, and called on players of Azur Lane to provide alternative terms for the game's personified warship characters.

[32] In September 2018, Yostar announced the new term would be "Kinetics Artifactual Navy-Self-regulative En-lore Node", abbreviated as "KAN-SEN" and is the backronym of the Japanese word "kansen" (艦船).

[40] Between November 27 and December 10, 2019, seven Hololive members (Murasaki Shion, Nakiri Ayame, Ookami Mio, Natsuiro Matsuri, Minato Aqua, Shirakami Fubuki and Tokino Sora) became playable characters as part of another collaboration.

[42] The collaboration event of anime television series SSSS.Gridman and SSSS.Dynazenon that ran from November 25 to December 8, 2021, saw the introductions of 7 limited-time obtainable characters; Rikka Takarada, Akane Shinjō, Yume Minami, Hass, Namiko, Mujina and Chise Asukagawa.

[43][44] In 2023, all previously featured characters returned in a rerun event that ran from July 20 to August 2, with the introduction of Princess Hime, and The 2nd from the film Gridman Universe.

[51] Yostar licensed the Japanese company GRSPER to create virtual reality wedding ceremonies with the game's characters in August 2018.

[52] The crowdfunding project was cancelled in October 2018 because GRSPER did not meet its funding goal and was having communication difficulties with voice actors and their agencies.

[72] Yostar head, Li Hengda, revealed that the animation project began in late 2017, when the game experienced its breakout in popularity.

[83] Azur Lane produces an educational video series hosted on YouTube called Learning Ships of the World with Mikasa Dai-Senpai (ja:三笠大先輩と学ぶ世界の艦船).

[85][86] In Japan, the game enjoyed an overwhelming surge in popularity after its release,[7] despite initial accusations by fans of Kantai Collection that it was a clone.

RPG Site wrote the game "acts as an important lesson on how a Chinese-made title can gain popularity in Japan by offering originality in its gameplay".

[7] Famitsu liked how the game depended very little on luck, let players develop their own playstyle, and was easy to pick up and play due to few microtransaction elements.

Hong Kong media outlet HK01 found Kantai Collection's complete lack of post-release improvements and overdependence on luck responsible for upsetting its own players, who switched contributing to Azur Lane's popularity.

[96] However, Shigetaka Kurita, director of Kadokawa Dwango corporation, criticized Azur Lane for lacking the sense of "tragedy and heroism" in Kantai Collection.

[97] In February 2021, one of the game's voice actresses, Ai Kayano, who recorded voice lines for Kaga, Atago, Renown, and Graf Zeppelin, was embroiled in controversy on Chinese social media as a result of a post regarding her February 11 trip to Yasukuni Shrine – a Shinto shrine often known as a subject of political controversy for the enshrinement of Japanese men, women, children, and soldiers who died in numerous wars involving Japan between the Meiji and Showa eras.