Adult people all over Japan had been captivated by 20th Century Expo, theme parks that reenacted good old days of the 1970s (the last days of Japan's high economic growth). One day the adults disappeared into the theme parks, leaving their children abandoned. That was a plot by "Yesterday Once More," an organization who despises the 21st century and tries to bring Japan back to the 20th century with the dreams and hopes. Shinnosuke and his parents, Hiroshi and Misae, fight against the plot of "Yesterday Once More" in order to live together with family in the 21st century.

(Source: Manabu Tsuribe)

Night Raid is the covert assassination branch of the Revolutionary Army, an uprising assembled to overthrow Prime Minister Honest, whose avarice and greed for power has led him to take advantage of the child emperor's inexperience. Without a strong and benevolent leader, the rest of the nation is left to drown in poverty, strife, and ruin. Though the Night Raid members are all experienced killers, they understand that taking lives is far from commendable and that they will likely face retribution as they mercilessly eliminate anyone who stands in the revolution's way. This merry band of assassins' newest member is Tatsumi, a naïve boy from a remote village who had embarked on a journey to help his impoverished hometown and was won over by not only Night Raid's ideals, but also their resolve. Akame ga Kill! follows Tatsumi as he fights the Empire and comes face-to-face with powerful weapons, enemy assassins, challenges to his own morals and values, and ultimately, what it truly means to be an assassin with a cause. [Written by MAL Rewrite]

Enforcer Teppei Sugou, former ace pilot of the National Defence Army's 15th Integrated Task Force, is visited by a scout from the Ministry of Foreign Affairs and invited to rejoin the military. While considering the offer, he recalls his last months of service. His last mission, Operation Foot Stamp, had been a highly classified military strike against the Southeast Asian Union. The operation quickly went south for the ground forces, and Sugou's First Guardian drone was ordered in as air support to drop emergency supplies for the ground units and then return to base. Following orders against his own judgement, Sugou abandoned his comrades on the field. Many lives were lost during the operation, including Itsuki Otomo, Sugou's commanding officer. However, three months later, following a massacre at the Ministry of Defence, Otomo was spotted at the scene on camera. Now a suspect in an act of terrorism, Sugou cooperates with Enforcer Tomomi Masaoka and CID Division One as they hunt his former mentor down.

According to HMV, the DVD & Blu-ray volume 7 of Ookiku Furikabutte ~Natsu no Taikai Hen~ will include an unaired episode 12.5. Director Mizushima posted in his blog that the special was made because they couldn't put the original manga episodes happened between the episode 12 and 13 within the TV series.