Akari Akaza, Chinatsu Yoshikawa, Kyouko Toshinou, and Yui Funami return to commemorate an exciting occasion! Despite their initial bizarre celebration ideas, they decide to hold a party at their Amusement Club room. With the help of friends from the Student Council, they start preparing for the big day—with a surprise planned for a special someone. Join the girls as they work together to create an enjoyable and memorable party, all the while interacting with one another with their cute and unique quirks. [Written by MAL Rewrite]

In the aftermath of the most devastating conflict mankind had ever experienced, the tiny island of Shikotan became part of the Sakhalin Oblast... and on the unhealed border in this remote corner of the world, friendship among children from two different countries timidly blossomed, striving to overcome language barriers and the waves of history. Inspired by true events. On August 15th, they told us we had lost the war. At that time, we did not really understand. Then one day, everything changed. Many soldiers, wearing uniforms we had never seen before, arrived on the island. That was the day I met Tanya.

Jiyu Nanohana is an ordinary schoolgirl until she runs across a scatterbrained 300 year old samurai who tells her that she is the reincarnation of Yagyu Jubei. With the help of the "Lovely Eyepatch" she transforms into the legendary swordsman whenever she needs to use his awesome fighting ability, which she needs to do quite often as a rival clan is dead set on conquering Yagyu to satisfy an old family grudge.

The year is 2148. Two years after the end of the original Fafner in the Azure TV series, Tatsumiya Island and its surviving residents have returned to some semblance of recovery. However, things have become desperate for our hero, Kazuki; nearly blind now, and partially crippled from his battles with the Festum two years earlier, he clings to the promise his fallen friend Soushi made to him to return to the island and set things right again. Kazuki's hopes flare when a lifeform is detected within an unmanned submarine that comes floating into Tatsumiya Bay one night, but the person aboard isn't Soushi; it is a mysterious "boy" named Misao Kurusu who may not be entirely human, and who claims to have been sent by Sōshi. With Misao's arrival, hostilities break out anew between the Human Army and the Festum, and the Fafner pilots are thrown into the most desperate battle of their lives - this time, with the fate of TWO races riding on their shoulders. 

(Source: Wikipedia)