Updated Timeline:
Unknown Time - Jaguar (Yoshimura Hyouma) forms the Superhuman Bureau. Episode 10.
October 14 - Jiro's father meets GaGon in the Pacific Isles, loses "Maria", a native shapeshifter? A month after World War 2 broke out. Episode 4.
December 16 - Mironu of the Japanese Immortal Family is captured by the American forces on Hawaii after his submarine is sunk. He joined the Japanese army in order for his family to avoid the family census. He gets experimented on and tortured for decades. Episode 9.
RWR: Kazuo Sakamaki (
https://en.wikipedia.../Kazuo_Sakamaki) the first Japanese soldier taken prisoner by the US in World War 2 when his submarine was beached.
August 17 - GaGon faces off against American Superhumans in the Pacific Ocean. 9 months after Pearl Harbor.
August 20 - Hitoyoshi Magotake finds baby Jirou in a crater in Hiroshima, with a shadow the dragon's shape. Episode 13.
RWR: the atomic bombing of Hiroshima on August 6, 1945
November 29 - Invisible Kaiju appears, Emi chooses to appear as an adult, Jiro's father finds him naked and unconscious. Episode 4.
January 34 - Flashback sequence. Giganto Gon breaks Jiro out of the laboratory where he's held. Jiro wants Giganto Gon to destroy everything. Episode 5.
Robot-GiGantor defeated by Rainbow Knight who saves Jirou (Episode 8), baby GaGon meets his adoptive brother. Episode 4.
March 38 - Rainbow Knight kidnaps Daitetsu Maki and other superhuman kids, to protect them and/or gain money for their release. Dies for it. Episode 8.
RWR: Yoshinori kidnapping-murders (
https://translate.go...t-text=&act=url)
Unknown Time - Jaguar (Yoshimura Hyouma) forms Infernal Queen, also known as IQ, or Advocates of Free History to better the future by removing evil. Episode 10.
July 40 - Judas is part of the criminal organization The Diamond Eaters, confronts Earth-chan and vows to become good. Episode 7.
January 41 - 6 months before Kikko joins. Grosse Augen first appears as a Kaiju vanquisher. Call for "more magic" instead of science within the Bureau is made. Episode 4.
June 30th 41 - The Beatles play in Japan, their powers bring forth more superhumans, or at least open the potential for some. Mountain Horse group becomes superhumans. Episode 6.
RWR: The Beatles did indeed make their first performance in Japan on June 30th, 1966.
July 41 - Kikko joins the organization, Jirou goes against orders and saves Grosse Augen. Episode 1.
Meta: Grosse Augen is probably mostly an Ultraman reference. Ultraman first aired in 1966 (Showa/Shinka 41).
Between July and August 41 - A month after Kikko joins, just before Fuurota joins. More Kaijus appear, various superhumans fight them off. We meet Earth-Chan and Kaiju-using robbers. Grosse-Augen "replacement" takes up the burden. Episode 4.
Meta: Earth-chan seems to be a reference to Astro-Boy.
August 41 - Fuurota joins the organization, kills the bug species. Kikko with the organization for one month. Episode 2.
RWR: A political clash (figuratively) called the "Black Fog" incident occured at the Japanese parliament in 1966 due to several political scandals for the ruling party (
https://translate.go...%2595%258C%2529)
November 41 - 3 months after Fuurota joins, humans confirmed as creating Kaijus. Mini-GaGon and Kaiju-lovers introduced as Fuurota's friends. Episode 4.
February 42 - Bombing incident with android detective. Episode 3.
June/July 42 - Master Ultima returns from Mars, Bureau leaders revealed non-humans, expose their own Kaiju-creating ring. Jiro unleashes his arm. Episode 4.
July 42 - USA throw away a Space Kaiju's remains near Okinawa. Kaiju-sympathizers grab remains and begin agitating against the establishment and the Superhuman Bureau. Episode 5.
August 42 - Protests by students begin, Jiro forced to become a Kaiju, faces off against Mega GaGon. Mega GaGon killed. Episode 5.
RWR: Japanese students protest against the US-Japan Security Treaty, escalating into a riot and at least one death at the hands of police.
RWR: The references to "Broken Lance" incidents of the US losing control of Kaiju is analagous to "Broken Arrow" (
https://en.wikipedia...gy#Broken_Arrow) incidents of the US losing nuclear bombs, specifically these three:
https://en.wikipedia...Base_B-52_crash ;
https://en.wikipedia...ea_A-4_incident ;
https://en.wikipedia...ares_B-52_crash
RWR: A US Military Fuel train derailed and caught fire in Tokyo (
https://translate.go...%BA%8B%E6%95%85)
September 42 - The Immortal Family cause an explosion, which they emerge fine from, and escape, apparently to alert Mironu who has been missing. The Superhuman Bureau find out the Americans are aware of immortal Japanese, and they know they're missing a member. Episode 9.
October 42 - Mountain Horse group tries their luck as superhumans and quits it. Fuurota infiltrates the Sugimoto media group. Episode 6.
October 42 - The superhuman Bureau recruits Judas after his release from prison. Face off against Earth-chan and try to get her aid in changing public opinion to sway protests against Japan joining the Earth Defence Force (against evil space-men). Earth-chan is given the ability to dream. Ullr (Kikko's familiar) plots with Emi. Episode 7
RWR: These protests are the October 8th 1967 Haneda protests, which blockaded the Haneda airport to try and prevent the Prime Minister from departing. One of the protesters was killed by a security force bus (said to have been driven by a fellow student) (
http://www.jag.ucla....i_ahr.114.1.pdf)
November 42 - Mountain Horse band brings down Sugimoto Media Group's plot to block superhumans' powers. Dee of Mountain Horse band dies. The Bureau now knows of the Sugimoto group as their enemy clearly. Episode 6.
December 42 - Kikko meets up with Nakagawa Jin, who researches superhumans and The Devil Realm, and who gives her special medicine. Episode 12.
January 43 - Daitetsu Maki, now Otonashi Yumihiko and the other kidnapped kids (presumably) are an unregistered superhuman group, BL Club, who stage thefts by "The Eye of Lucifer", Rainbow Knight's old nemesis. Yumihiko and Jirou speak of morality. Superhuman Bureau is asked to stop opposing the FDE. Episode 8.
April 43 - IQ (Infernal Queen) appear to take out the Superhuman Bureau who they deem evil for controlling superhumans, working with Americans, and lying to the public. Jaguar (Hyouma) #3 takes kills his #2 version, IQ's leader, and his Time Patrol watch becomes the basis for the Time Travel research program. Episode 10.
June 43 - USS Antares, a superhuman-powered submarine is brought over by the USA over to Japan. Turns out it makes use of enslaved superhumans. Phantom Sword Claude destroys it, revealing said fact. Jirou turns down an offer by Imperial Ads who say they only want human Superhumans. Protests and revealing to the public the American wrongdoings, a scheme to officiate Superhumans as part of law enforcement agencies is pushed forward by the former Defense Minister who's behind Imperial Ads. Episode 11.
RWR: Visits of American nuclear submarines to Japanese ports, many of which were protested against by leftist Japanese (e.g.:
http://archives.chic...sub-visits-plan)
August 43 - Kikko sees Claude killing medical personnel, turns into devil form, finds out she knows Claude. Episode 11.
RWR: Japan's first heart transplant was conducted at a university in Sapporo in August 1968, the same time and place as Claude's killings. The real-life heart transplant resulted in a distrust of organ transplanting due to concerns of the presiding doctor erroneously evaluating the transplanter's brain death.
Immediately After - Golubaya Laika, a Soviet Superhuman who's anti-war flies towards Japan, is shot down by the American-siding Master Ultima for passing over the facility where the Japanese and Americans experimented on superhumans. Jirou finds out his father framed and killed The Rainbow Knight who tried to save kids from being experimented on. Claude is revealed to be Jin, Jirou's childhood friend, who was experimented upon. The Chief is revealed to be an alien who's trying to help humanity ascend via superhumans. Kikko helps Claude. Episode 12.
RWR: Golubaya Laika is almost certainly a reference to Yuri Gagarin, the first human in space, who also died in 1968 (in a plane crash). His name is probably a combined reference to Gagarin and Laika (the first dog in space).
Immediately After - The truth of the Japanese-American Superhuman experiments is revealed to the public. The government tries to suppress said information. Chief Akita believed dead, Jin (Claude) and Kikko believed guilty, and are missing. Episode 13.
October 8th 43 - American Fuel Tanker ignites protests by Japanese anti-war students. Episode 13 reference.
October 21st 43 - World Peace Day (our world's is in September 21st), Chief Akita kills and assumes the spot of the pro-Imperial Ads politician who can pass or deny the revised Superhuman Secrecy/Rights Law. Students go on protests against the government for the experiments. Government uses force to crush protests, Claude is revealed to be evil and Jirou defeats him. Emi suppresses Devil Queen Kikko. Earth-chan is broken. Rule-changes denied, and Jirou leaves the bureau. Episode 13.
RWR: Peace Day protests = New Left protests (
https://en.wikipedia...panese_New_Left) against the US-Japan Mutual Cooperation Treaty
~Year 44 - Kaiju wave of attacks dies down. Episode 5 reference. Likely a reference to the 990 days of the protests following the Haneda Protest ending. Episode 7.
September 44 - Mironu of the Immortal Family is released by the Americans who follow him to try and eliminate the family. The Superhuman Bureau and Jirou try to defend them but are defeated by the American robot, the family survive on their own. Jirou clashes ideologically with the Bureau members. Chief Akita's absence is noted upon. Episode 9.
Meta: The Immortal Family is a reference to Sazae-san and that show's incredible longevity. Furthermore, this episode was written by Masaki Tsuji, who wrote the very first episode of Sazae-san.
Meta: The USA combining robot looks very similar to Optimus Prime...
RWR: The river and robot barf scene could possibly be a reference to the mercury poisoning by the Showa chemical plant in Kanose Village in (
https://en.wikipedia..._of_Showa_Denko), but the timing is wrong.
October 44 - Jiro tries to recruit Mountain Horse and they decline. Jiro's quest is revealed as gathering superhumans to take on the Superhuman Bureau. Superhumans appear to be illegal. Fuurota goes and meets him. Episode 6.
~Year 45-46 - Osaka Earth Expo, relevance unknown. Episode 6 reference.
RWR: "Expo '70", a world's fair held in Osaka in 1970 (
https://en.wikipedia.org/wiki/Expo_'70)
April 46 - Jiro is an enemy, ex-Grosse Augen helps him, Kikko declares love. Episode 1.
Meta: Continuing the Ultraman reference, Grosse Augen returns in Shinka 46 (1971), the year "The Return of Ultraman" aired.
November 46 - Jirou takes on the role of the fugitive in order to protect superhumans. Episode 13 preview for cour 2.
February 47 - The male half of Megasshin returns (RWR: return of Shoichi Yokoi to Japan after he hid in Guam for 28 years since World War 2) and merges with the female half. Raito now fugitive. Episode 3.
April 47 - Judas, Jirou, and Megasshin (fused android) more break into a lab to retrieve Earth-chan's stasis/broken down form, vowing to return her to her former glory. Episode 7.
October 47 - Jirou fights Yoshimura (time-controller, "Jaguar"), Restored Earth-chan intervenes, and then so does Daitetsu. Episode 8.
August 48 - Bug lady comes back for Fuurota, he learns what he's done, gets saved and comforted by Jirou. Episode 2.
25th Century - Jaguar (Yoshimura Hyouma) is sent back in time, as a member of Time Patrol. And as someone who tries to save superhumans, and as someone who tries to build a different future. Episode 10.