Hatsuharu as commissioned in september 1933:
this was the first IJN destroyer-class to sport a forward superfiring turret, a single 5-inch guns sat on a deckhouse above n°1 twin turret and the full gun armament was five 5-inchers in two twin and a single turret; torpedo armament consisted in three triple 610mm type 90 torpedo tubes (plus reloads) fitted with splinter-protection encasing, another fist was the
superfiring placement of the thrid set, whose reloads where also fitted in a higher position, above the aft deckhouse.
another feature of this class was the offset placement of the after-funnel and the aft deckhouse: the fist was shifted to starboard in order to mantain balance with the port-fitted torpedo reloads for mounts 1 and 2; the latter was angled with the fore part under n°3 torpedo tubes placed more towards the starboard side and the aft part under the reloads beign more towards the port side.
this large armament setup placed even high above the waterline, copupled with the high superstructures, fitted on a relatively light hull (1.510 long tons) made the ships dangerously overloaded and top-heavy; the first issues came into light during the trials, Hatsuharu rolled 38 degrees at full speed with the rudder set at 10°, prompting the naval staff to request a refit to correct the issue.
Nenohi as of 1933:
She and Hatsuharu where the only two (out of six) to enter service as originally designed, the others where modified while they where under construction; Nenohi was slighty different, with a small antenna fitted above the compass platform and some more riggings.
Hatsuharu as of 1934:
the addition of 300mm torpedo bulges on each side of the hull was an early measure to improve the stability issues of the Hatsuharu class ships; this feature, implemented in late 1933, proved quickly to be useless and when the ships where extensively reconstructed starting in mid 1934 the bulges were removed.
Hatsuharu as of 1935:
after the capsizing of the torpedo boat Tomozoru the top-heavyness of the Hatsuharu class could not be overlooked anymore, massive modifications where implemented to the project, with Hatsuharu herself and Nenohi beign returned to the naval yards to be refitted; Wakaba and hatsushimo were modified before enterng service, while Ariake and Yugure were modified even before launch.
the aft deckouse and the third torpedo tubes set where removed and the single 5-inch gun was relocated there, the bridge structure was rebuilt in a smaller fashon, the compass platform disappeared and both the forward and aft masts where slighty lowered; the forward torpedo mount was lowered by 300mm, the funnels by over a meter, the searchlight and machine gun platforms by almost two.
to mantain stability 84 tons of ballast where added to the keel and an automatic system which filled part of the fuel tanks with seawater to compensate for the consumption of fuel and resulting rise in the center of gravity and hence loss of stability installed; the hull was also further strenghtened after the 4th fleet incident in 1935, displacement rose to over 1.800 tons and speed fell from 36.5 to 33.5 knots.
Yugure and Ariake as of 1936:
both where launched and completed to the modified design, moreover they had more beam thant the first four ships and where armed with model C turrets instead of model B ones; those further modifications sometimes led them to be addressed as a separate class.
Wakaba as of 1937:
Nenohi as of 1942:
Nenohi sank with 188 dead on July 5th 1942, torpedoed by USS Triton near Attu; no wartime modifications where done on her.
Ariake and Yugure as of 1943:
both where refitted in early 1943 and saw the addition of three twin 25mm machine gun mounts, two of them replaced the old single 40mm machine guns abreast the second funnel, the other was fitted on a platform in fron of the bridge.
Yugure was sunk with all hands by us TBF Avengers in july 20th 1943 while on a troop transport run to Kolombanara, Ariake followed her eight days later, sunk with 7 dead after beign bombed by B-25 off Cape Glouchester, Papua New Guinea.
Hatsuharu and wakaba as of 1943:
by late 1943 both hips had recieved a type 22 surface search radar on the foremast, the single 40mm machine guns where replaced by twin 25mm ones, two triple mounts where also added, one on a platform ahead of the bridge, and the other on top of a deckhouse built in place of the single 5-inch (127mm) gun wich was landed.
Hatsushimo as of 1943:
in 1943 Hatsushimo had the single 5-inch gun removed and replaced by a triple 25mm machine gun, also another three twin mounts where added, two in place of the older 40mm machine guns and the latter on a platform fitted in front of the bridge
Wakaba as of 1944:
By october 1944 Wakkaba had recieved extra 25mm machine guns and a type 13 air search radar on the mainmast; she was sunk in the Battle of Leyte Gulf by aircraft from USS Franklin (CV-13)
Hatsuharu as of 1944:
refitted like Wakaba by the time of the Philippine campaing, Hatsuharu was sunk in Manila Bay on the night of 13 November during an an air raid.
Hatsushimo as of 1944:
during 1944 Hatsushio recieved a type 22 surface search and a type 13 air search radar, ten single 25mm machine guns were also added
Hatsushimo as of april 7th 1945:
by the time she escorted Yamato during operation ten-go Hatsushimo had underwent the portholes-sealing treatement, other than that another five single 25mm machine guns and four 13mm mounts were added, and the bridge was slighy modified; Hatsushimo survived the ten-go onslaught almost unscathered, and rescued survivors from Hamakaze, Yahagi and Yamato herself, but her luck ran out on july 30 1945, she hit a mine in Miyatsu Bay, near Maizuru, while trying to escape an US air raid, becoming the last IJN destroyer to be sunk in the war.