Upotte!! is not just any anime detailing guns, the guns themselves live to tell about it! Upotte!! follows the story of anthropomorphized guns FNC, M16A4, SIG SG 550, and L85A1 (Yes, that's their actual names!) and their adventures in Seishou Academy. The school is divided into three different groups, Sub-machine guns (Elementary School), Assault Rifles (Middle-School), and Battle Rifles (High-school). Their goal in the school is to come out as the most useful weapon there is. Everything in their life proceeds as normal, but sometimes things get a teensy out of control when a human suddenly comes along and have to take responsibility of not just one rifle, but a whole class, bringing along no gun experience whatsoever! This media follows through their life in Seishou Academy and the (mis)adventures the human and guns have together.
The following weapons were used in the anime series Upotte!!:
What appears to be a Glock 26 is depicted in "Sing! Compete!" when the narrator explains the use of red dot sights.
Submachine Guns
Fabrique Nationale P90 TR
An FN P90 TR is partially seen in "Sing! Compete!".
Heckler & Koch MP5A2
A Heckler & Koch MP5A2 is shown during a background explanation of 5.56 and 7.62 NATO rounds in "Go for it! Pass it!". An actual MP5A2 is fired by MP in "Wash and Scrub!"
Ingram MAC-10
A picture of an Ingram MAC-10 is seen in "Wash and Scrub!" when MP explains why M-10 suddenly stopped talking mid-sentence after a quick-fire non-stop tirade about a classmate. This is a reference to the extremely high rate-of-fire on some MAC-10 variants, which could peak at around 1,200 RPM (though it's mentioned M-10 herself fires at 1,090 RPM).
M1928 Thompson
A Thompson M1928 with a drum magazine is shown in "Be Afraid! Visit!", which oddly shows Thompson (the elementary school teacher and personification of the Thompson submachine gun) on the cover.
MP40
An MP40 is shown in "Wash and Scrub!" when the narrator explains the background of modern submachine guns.
Assault Rifles
AK-47
An AK-47 is seen in "Sing! Compete!" when the narrator explains the background behind the conflict between the M16 and the AK-based rifles.
AK-74
An AK-74 is seen in "Burn up! Go Mad!" as the main weapon of 74. A few AK-74s are seen with other students of Red Steel High in "And then! Upotte!".
Armalite AR-18
An Armalite AR-18 used by 18 (Ichihachi in Japanese) can be seen on the shooting range next to L and Aug in "Grip and Hold!". 18 uses the AR-18 in the jungle wargames in "Sing! Compete!".
Bushmaster ACR
A poster illustrates the Bushmaster ACR in "Sing! Complete!" with details on the disassembled parts.
CETME Model L
A CETME Model L is seen in "Sing! Compete!" wielded by Model. It's also seen in Curly's gun shop, as well as being on the sign for the shop.
Colt AR-15
Colt M16
A Colt M16 is seen in "Sing! Compete!" when the episode shows the evolution of the M16 series and when the narrator explains the origin of the rivalry between M16 and AK rifles.
Colt M16A1
A Colt M16A1 can be seen in the second episode when the M16A1 is compared with the A4 in terms of firing rate in "Go for it! Pass it!". A M16A1 is also seen in "Wash and Scrub!" and in "Sing! Compete!".
Colt Model 653
A Colt Model 653 carbine fitted with a 16" sporter barrel is seen in the hands of an American soldier in "Sing! Compete!".
A Colt M16A3 (basically a full-auto M16A2) can be seen in "Sing! Compete!".
Colt M16A4
16 (Ichiroku in Japanese) is the personification of the Colt M16A4 Assault Rifle, first appearing in "Grip and Hold!". Examples of the M16A4 are first seen in "Sing! Compete!". What appears to be M16A4s are seen in a flashback in "Take it! Hurry!". In "Graze it! Beat it!", the chamber of 16's M16A4 becomes fouled due to bad powder, causing the weapon to jam with each round fired, forcing her to use the forward assist after every shot and complain that she's not supposed to be a bolt action rifle.
Colt M4A1
A Colt M4A1 is depicted in "Wash and Scrub!" in the hands of a British SAS soldier during an oral history narration of the L85A1. It has a holographic sight with a magnifying scope.
Enfield L85A1
L is the personification of the L85A1, first appearing in "Grip and Hold!". She adores Fal and often jams, which is unfortunately true as the British and the Jamaicans (A major user of the L85A1 since 1992) often encountered jamming issues as a major source of discontent for the rifle before Heckler & Koch was able to improve the rifle to bring it the L85A2 standard. The L85A1 appears in "Wash and Scrub!" during a narrator explanation on how the rifle was made.
Enfield L85A2
The Enfield L85A2 appears in "Wash and Scrub!" when the narrator explains how the L85A2 was created to handle the defects from the A1 model.
FARA 83
A FARA 83, made by Fabrica Militar de Armas Portatiles Domingo Matheu (Domingo Matheu Portable Military Factory), is seen in "Sing! Compete!", wielded by Fara.
FN FNC
Funco is the personification of the FN FNC Assault Rifle, first appearing in "Grip and Hold!". Hilariously, Genkoku first referred to her as the 'girl with the thong', a reference to the fact FN FNC's came with skeleton stocks. The FNC Funco wields appears to be based on the civilian semi-auto version, since it has a sling mount instead of the bayonet lug under the barrel.
GIAT FAMAS G1
A GIAT FAMAS G1 is seen in "Wash and Scrub!" when bullup rifles are explained by the narrator.
The folding stock of a Howa Type 89-F is seen in "Sing! Compete!".
Israel Weapon Industries Galil AR
Galil fires an IWI Galil AR in the shooting range alongside Sako. She first appears in "Sing! Compete!".
Kbk wz.88 Tantal
A Polish Kbk wz.88 Tantal, the Polish equivalent of the AK-74, is wielded by a Red Steel High student during the shootout in Atami in the episode "And then! Upote!".
Norinco Type 86S
A Norinco Type 86S is used by 86 (or "Type 86") in "And then! Upotte!" as her main weapon with the Red Steel High faction.
Sako Rk95 Tp
A Sako Rk95 Tp is used by Sako as her main assault rifle, appearing first in "Sing! Compete!". She first uses it in "Graze it! Beat it!!".
SIG SG 550
Sig is the personification of the SIG SG 550; smart yet somewhat of a ditz. She first appears with the rifle in "Grip and Hold!". She is depicted as being the most accurate of the main four assault rifles, able to effectively engage targets at ranges that would normally be associated with the larger-caliber battle rifles.
A ST Kinetics SAR-21 is used by Sar in "Sing! Compete!". Like Aug, she wears glasses to represent the SAR-21's built-in optics. It's also seen in Curly's gun shop.
ST Kinetics SR-88A
An ST Kinetics SR-88A is used by 88 in "Sing! Compete!". It's also seen in Curly's gun shop.
Steyr AUG
Aug is the personified version of the Steyr AUG; she wears glasses like Sar, representing the AUG's built-in optics. She first uses it in "Graze it! Beat it!!", changing hairstyles by removing the short wig to her original long hair to indicate the use of a standard barrel-based AUG. Crunchyroll's subs consistently mis-indentify the weapon's country of origin as Australia, contrary to the narrator's correct mentioning of Austria as the AUG's country of origin. It's also mentioned that the AUG can mount a heavy barrel and become a Squad Automatic Weapon (likely referring to the AUG HBAR), however the standard-length AUG is shown when this is being explained, likely an oversight. When in this persona, Aug's confidence increases to the point where she becomes almost overbearing.
T91 Carbine
The T91 carbine is seen in "Sing! Compete!" in Curly's gun shop. The T91 is first used by Tei in "Graze it! Beat it!!". Her stock (panties) gets shot off by 16 during their wargame, but is recovered afterwards. Her trademark six-pigtail hairstyle is likely a reference to the insignia of the 205th Armory, T91's manufacturer.
Battle Rifles
Enfield EM-2
An Enfield EM-2 is seen in "Wash and Scrub!" when the history of the L85A1 is explained.
Enfield XL64E5
The Enfield XL64E5 is seen in an oral narration of the creation of the L85 series in "Wash and Scrub!".
Fabrique National FAL
An FN FAL appears in "Wash and Scrub!" when the narrator explains to the audience how the L85 was created.
Royal Small Arms Factory L1A1 SLR
Funco's elder sister Fal is based off the FN FAL, more specifically the British L1A1 SLR variant. She is described as being beautiful and smart. Fal appears in "Grip and Hold!". The rifle appears in "Wash and Scrub!" when Fal explains the origin of the L1A1. Even if Fal is depicted as being based on the British L1A1 model (so semi-automatic only), while confronting her younger sister at the fountain in "Go for it! Pass it!" she is seen firing a burst in fully automatic fire, much like the original Belgian model. This is apparently a reference to a field-modification that Australian troops did to their L1A1s during the Vietnam War to lock their weapons in full-auto.
Heckler & Koch G3A3
G3 is the Heckler & Koch G3A3. She has several younger sisters in middle and elementary school (i.e. the HK33 and MP5 series'). She first appears in "Grip and Hold!". The rest of the H&K family, seen in the manga, consists of HK33E, G41, and G36 in middle school, HK53 (due to being MP5-sized) MP5A2, MP5SD, MP5K, UMP, and MP7A1 in elementary school, and HK32 who attends Red Steel High due to her caliber. 53 appears in "Wash and Scrub!", and (along with G3 and MP) UMP, MP5K, MP7A1, and four others who are off-screen appear in "Behold! Laugh!", however none of their guns are seen in the show. It's most likely that MP5SD doesn't talk (or doesn't talk much, at least), with HK32 presumibly being the one not present in "Behold! Laugh!".
Springfield M14
16's elder sister 14 (Ichiyon in Japanese) is based off the M14. She first appears in "Grip and Hold!". A few M14s are seen in "Sing! Compete!". 14's accuracy when firing her rifle in full auto is non-existant; 16 even claims that the spread of her rounds is roughly 10 meters. This is a reference to the M14 being notoriously difficult to control in full-auto due to the heavy recoil of its 7.62x51mm ammo.
Semi-Auto Rifles
M1 Garand
An M1 Garand is shown in "Take a Look! Scold Someone!", which is a wooden replica of the gun placed on the sign on the entrance to the Seisho Academy annual fair.
SKS
An SKS rifle appears in "Wash and Scrub!" during the explanation on the origin of bullpup rifles.
Shotguns
Saiga 12K
A Saiga 12K is seen in "And then! Upotte!" as the main weapon of Saiga when she fights on behalf of the Red Steel High faction.
Remington 870
A Remington 870 is used in "And then! Upotte!" to demonstrate the difference between a traditional pump-action shotgun with a non-detachable tube magazine and a self-loading shotgun, such as the Saiga series, loaded with detachable box magazines.
Machine Guns
Browning M2HB
A Browning M2HB is seen on top of a Stryker ICV in "Take a Look! Scold Someone!".
Sumitomo M2HB
A Sumitomo M2HB, which is the license-made version of the Browning-made M2, is shown in "Take a Look! Scold Someone!".
M61 Vulcan
M61 Vulcans are the main machine guns of F-22 Raptors seen in "Take a Look! Scold Someone!".
RPK
A RPK-47 light machine gun is used by RPK as her main weapon in "And then! Upotte!".
Grenades
Mk 2 hand grenade
A Mk 2 hand grenade is shown in "Take a Look! Scold Someone!", which is actually pineapple pie made like an actual Mk 2.
Others
Curly's Gun Store Racks
In Curly's gun store in "Sing! Compete!", several assault rifles are portrayed as being sold in the world of "Upotte!".
RPG-7
An RPG-7 launcher tube in shown in "Take a Look! Scold Someone!"