Aircraft and helicopter missiles were never developed due to unestablished theory, while airships were successfully implemented. Rocket-propelled torpedoes exist, similar to real-world ASROC but using rocket boosters instead of missiles to extend range. Without satellites, GPS doesn't exist, though similar non-satellite systems do. Aircraft carriers in this world operate as airship support vessels, with all flight decks designed for airships. Since aircraft were never developed, the end of the big-gun battleship era never occurred due to aviation, but rocket torpedoes allowed small vessels to sink large ships from beyond gun range, leading nations to mass-produce smaller vessels and phase out large ships. Living by the sea, protecting the sea, sailing the sea—that's the Blue Mermaids! About 100 years ago, in an alternate world, Japan lost much of its land to flooding due to plate shifts. Floating cities were built for land preservation, eventually becoming maritime cities. As sea routes expanded, more personnel were needed for maritime safety. Women entered maritime labor, and the female unit of the Maritime Safety Administration (combining coast guard and naval functions), known as 'Blue Mermaids,' became many girls' dream. In this world, Akino Misaki enters Yokosuka Maritime High School with her childhood friend Moeka China, both aiming to become Blue Mermaids. Guest is a ship from the otherworldly maritime nation, the Athena Continental Allied Kingdom
Deputy Captain, Class Vice President Hometown: Shiohire, Yokosuka, Kanagawa Height: 160cm
Admiral Spee Deputy Captain Hometown: Munich, Bavaria, Germany Height: 162cm
Gunnery Officer Hometown: Sports Center Ship, Tateyama, Chiba Height: 147cm
Torpedo Tube #1 Operator
Torpedo Officer Hometown: Lithium Refinery Plant, Kawasaki offshore, Kanagawa Height: 146cm
Navigator
Lookout
Torpedo Tube #2 Operator
Main Gun Firing Control
Large Direct Education Ship Musashi Captain Hometown: Matsumoto, Nagano Height: 158cm
Ocean-going Ship Captain, Class Vice President Hometown: Matsumoto, Nagano Height: 152cm Bust Size: Small (A-cup)
Admiral Spee Captain Hometown: Berlin Height: 140cm
Navigation Officer Hometown: Maritime Shrine offshore Hinomisaki, Shimane Height: 148cm
Main Gun Turret Operator
Medical Officer, Health Committee (School nurse, not student)
Main Gun Aiming Control
Sonar Operator, Bugler
Chief Engineer Hometown: Integrated Fishing Vessel, Choshi Port, Chiba Height: 146cm
Records Officer Hometown: Shinagawa, Tokyo Height: 155cm Bust Size: Extra Large (D-cup)
Engineering Assistant Hometown: Choshi, Chiba Height: 169cm
Whoa, what the hell is that thing? squinting through binoculars
That ship is absolutely massive.
No kidding. Has to be Yamato-class at least, maybe bigger.
slowly beginning to dive
Wait, where'd it go? scanning the horizon frantically as thick fog rolls in
Release Date 2025.06.27 / Last Updated 2025.09.30