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Japanese Space Defense Force (SDF)
with thanks to Bryn Monnery for getting me started

The Japanese Space Defense Force consists of three components, the Imperial Japanese Space Navy, their ground wing, the Imperial Japanese Space Marines, and the space components of the Colonial Self Defence Forces of Amatersau, Daikoku, Shungen and Tosashimizu. Each of these has evolved separately, but have been put under joint command.

Note on canonicity: This is based on canon material, but as the date of 2303 is after the first series of battles with the Kafer there are a number of changes in ship quantity and basing. Items shown in red are still being fiddled with.

In the early 22nd century 3 nations developed the Stutterwarp Drive independently, France, Bavaria and the UK and formed the European Space Agency, with the aim of exclusively exploiting this discovery. The main problem with the stutterwarp is that it required a core of tantalum-181, the rarest metal in the universe, and so the ESA nations set about trying to gain a monopoly on global tantalum. However, when Spain was invited into ESA for its tantalum, it refused and sold the story to the world.
Japan, caught off guard, immediately took stock of its position. Japan had no tantalum in the whole of the Empire, but some Southern African nations were willing to sell theirs for an enormously high figure. With great foresight, the Japanese paid Mozambique and Azania for a significant amount of tantalum. With the colonization issue settled, Japan settled on Tirane in 2168.
Japan was delighted when it turned out their colonial territory contained the only tantalum deposit on Tirane, however, the territory was disputed with the Argentine colony of Santa Maria and then when Australia put the colony of New Canberra between the two existing colonies. A small war broke out over control of the tantalum, and Japan saw need of an armed Space Force. The Imperial Japanese Space Navy was formed in 2170, to counter the Argentine space fleet which had just commissioned a third warship, Adrimante Brown. Japan's first warship, the Destroyer Yamato was commissioned in 2173. However there were no space engagements during the conflict, which was finally resolved by the formation of an international corporation to exploit it in 2196. The Argentines continued to take their share of tantalum even after the folding of Santa Maria in 2207.
In 2208, a private company, the Shungen Corporation, backed by the Japanese government settled a refuelling Outpost on Davout, cutting the French out of the loop entirely. Even better, excess fuel was sold to other nations, breaking the French stranglehold on trade in the Chinese Arm. The outpost was fully operational in 2211. This enabled Japan to move into the much better colony world of Beta Hydri-2 (Daikoku), establishing the colony there in 2213, only 8 years after the Japanese pioneered the system. The colony fared so well that in 2237, a second territory was established in the system, this time on the innermost moon. While the main colony was primarily agricultural, the lunar colony was a mining facility. The hopes that the metals mined there could bring industry to Daikoku were fulfilled in full.
Around the same time, Arabia gained independence from France, and decided it wished to have a colony of its own. However, it would never gain tantalum, and so could never become a colonizer. However, approaches made to Japan were met sympathetically, the Arab government came to a deal. Arabia could colonize Beta Hydri, but Japan took first refusal over mineral rights, and all trade would be carried on Japanese vessels.
Japan's latest colony is on 61 Ursae Majoris-3 (Joi), settled in 2257. Japan has been aggressive in her colonization, and this has brought her into conflict with other nations.
The Central Asian War had been underway for several years when Japan became involved, providing them with their first space war. Since Manchurian policy in the war had been one of aggressive raiding of merchant vessels, it was decided to organise convoy systems immediately. The colonies on Tirane and Joi were protected by French fleet elements, but Shungen and Daikoku were totally undefended. Immediately a squadron warped to Daikoku and planetary defences were constructed. Manchu military vessels continued to transit the system, but despite French offers of a fleet to blockade the system, the Japanese stuck to a rigidly defensive posture.
Meanwhile, Japanese units were engaged in hunting down Manchu raiders on the French Arm, but they never managed to discover that Manchurian operations were so successful because they had a base of operations in theatre. As the CAW ended, Japan found themselves involved in trying to assist the French in the 61 Ursae Majoris system. The French Garrison Squadron had been defeated at the Battle of Two Fires (1st Joi) and had lost control of the system for almost a year until an attack fleet re-established French Superiority in the system. The Elysians were winning their independence. Towards the end, the Japanese 1st Marine Division boarded their transports and set off for Joi, to reinforce the French, only to find when they arrived, the French had surrendered.
In the aftermath, with French and Manchurian withdrawal from the system, two powers decided the future of Elysia, Hanover and Japan. Hanover was manoeuvring to establish a single German Empire, incorporating all the German speakers of Europe and all the German speaking off-world colonies. Things finally erupted in 2292 with the annexation of Bavaria and the establishment of the new German Empire. The balance of power on Joi was altered when a powerful German squadron, including the former Bavarian flagship, Bayern entered the system. The Japanese and Germans have been facing each other off here ever since.

Order of Battle
The Imperial Combined Space Navy consists of four Fleets. Each is a self-contained fighting unit of various sizes. In addition to the main fighting vessels, each fleet has its own Supply Transports, Couriers, Troopships and Marines. However, much of the support elements are theoretical. While vessels have been tasked, they spend most of their lives doing government transport work.
Symbol Qty Class ship Pics Mug
BC (battle cruiser) 2+2 Yamato Takeru 1  2 .
CG (missile cruiser) 5+3 Sakurajima 1 1
DD (destroyer) 3 Hyogo (old) 1  2  3 .
DD (destroyer) 9+3 Kanagawa (new) 1  2  3 .
FF (frigate) 17+4 Kuroda Nagamasa 1  2  3 .
Fighter 48 Sakura Kagero Kamakiri . .
ODI (orbital fort) 4 . . .
CV (carrier) 2 Katsuragi . .
OG (orbit-ground lander) 4+2 Leon . .
Group shots . . 1  2  3 .
     Number shows in-service and under construction

1st Combined Fleet (Earth)
Until the response to the Kafer threat, the 1st Combined Fleet was by far the largest fleet in the Combined Navy, and is an impressive formation. At its core are nine mainline fighting ships, including the massive Yamato Takeru, a Fighter-carrying Battlecruiser. Most of these ships are now
Nissho Station “úÍŠî’n
IJS-BC01 Yamato Takeru ˜`–Ò with
8 Sakura-class Fighters (Flag)
IJS-CG01 Sakurajima ÷“‡ with 4 Sakura-class Fighters
IJS-CG02 Asahi ˆ® with 4 Sakura-class Fighters
IJS-DD02 Hiroshima L“‡
IJS-DD08 Karafuto@ Š’‘¾
IJS-DD09 Mie@ ŽOd
IJS-FF05 Matsudaira Tadayoshi ¼•½’‰‹g
IJS-FF06 Tsutsui Sadatsugu “›ˆä’莟
IJS-FF07 Arima Toyouji —L”n–LŽ
IJS-FF11 Ikoma Kazumasa ¶‹îˆê³
IJS-FF12 Kanamori Nagachika ‹àX’·‹ß
1st Imperial Marine Brigade
2nd Combined Fleet (Tirane)
2nd Combined Fleet is primarily a flag showing fleet, with no major enemies it is regarded as a training and proving ground for the navy. As such, it has the oldest vessels in the JCSN.
Amaterasu Station “VÆŠî’n
IJS-DD01 Hyogo@ •ºŒÉ (Flag)
IJS-DD06 Nagano@ ’·–ì
IJS-DD07 Niigata@ VŠƒ
IJS-FF01 Kuroda Nagamasa •“c’·­
IJS-FF03 Hosokawa Tadaoki ×ì’‰‹»
IJS-FF04 Ii Naomasa ˆäˆÉ’¼­
8 Sakura class Fighters
4th Imperial Marine Brigade
3rd Combined Fleet (Daikoku)
3rd Combined Fleet has declined in strength in the last 10 years, with vessels being pulled to the 1st and 4th Fleets in light of the reduced Chinese threat. It now functions mainly as a "trip-fleet", making sure any potential invader has to fight to take orbit, and providing sufficient time for a courier to make outsystem towards Earth and bring up the 1st Fleet.
Daikoku Station ‘单Šî’n
IJS-FF02 Honda Tadakatsu –{‘½’‰Ÿ
IJS-FF13 Kato Yoshiaki ‰Á“¡‰Ã–¾
IJS-FF14 Furuta Shigekatsu ŒÃ“cdŸ
IJS-FF15 Kyogoku Takatomo ‹ž‹É‚’m
8 Sakura class Fighters
4th Combined Fleet (Joi)
With the appearance of the Kafer, the 4th Combined Fleet was extensively expanded by transfer of major fleet assets from the 1st Combined Fleet. From about 2290 the 4th Combined Fleet has been the major out-system deployment of the IJCSN. Additionally, the Japanese have their 3rd Marine Brigade and Colonial Defence Forces ready for a contested jump into Halbsiel airspace.
Tosashimizu Station “y²´…Šî’n
IJS-BC02 Œ¹‹`Œo Minamoto Yoshitsune (Flag)
IJS-CG04 Kuttara ‹ä‘½Šy with
4 Kagero-class Fighters
IJS-CG03 Aso ˆ¢‘h with 4 Sakura-class Fighters
IJS-DD05 Kanagawa _“ސì
IJS-DD10 Yamagata ŽRŒ`
IJS-DD03 Chiba@ ç—t
IJS-DD11 Okinawa@ ‰«“ê
IJS-DD12 Kochi@ ‚’m
IJS-DD13 Tochigi@ “È–Ø
IJS-FF08 Asano Yukinaga ó–ìK’·
IJS-FF09 Fukushima Masanori •Ÿ“‡³‘¥
IJS-FF10 Ikeda Terumasa ’r“c‹P­
IJS-FF16 Oda Yuraku D“c—LŠy
IJS-FF17 Tanaka Yoshimasa “c’†‹g­
8 Sakura-class Fighters
6 Kagero-class Fighters
IJS-OG1 Leon (troops)
IJS-OG3 Toro (heavy equipment)
IJS-OG4 Buwaya (supplies)

IJS-OG2 Pating (troops)
2nd and 3rd Imperial Marine Brigades
61 Cygni battlegroup (Note on canonicity: The entire 61 Cygni section is non-canon)
IJS-CG05 Nasu “ߐ{ (Flag)
IJS-DD10 Yamagata@ ŽRŒ`
IJS-CV01 Katsuragi Š‹é with
20 Kamakiri-class Fighters
IJS-CV02 Hiei ”ä‰b with
8 Kagero-class and 12 Kamakiri-class Fighters
IJS-FF18 Terazawa Hirotaka Ž›‘òL‚
IJS-FF19 Todo Takatora “¡“°‚ŒÕ

Ship Design

Japan has developed a very different design philosophy to the mainstream, and the salient points are:

  • No Nuclear Weapons
  • Heavy Screening and Armour
  • Reasonable Speed
  • Long Range (12 weeks)
  • Fighters carried at Cruiser level
  • No Integral Assault Capacity

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These web pages developed and maintained by Terry A. Kuchta
This page created 24 May 2008 and last revised on 26 May 2008.
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