The story follows the school life of the three girls, Yuzuko, Yukari, and Yui, who join their high school's Data Processing Club. The odd friendship between the three make for wacky humor in even the most mundane of events.

It began in 1945, at the end of the Pacific War. Alien invaders filled the earth's Skies, and mankind was forced to confront an unprecedented threat. For the first time in human history, people of all cultures came together under one banner. This war has now been raging for over fifty years. Countless lives have been lost, and the Japanese military is now forced to rely on young people such as Atsushi Hayami and his high school class, also known as Unit 5121. This new generation fearlessly struggles on with the aid of the HWT humanoid combat machines and the devastating PBE bomb. (Source: Media Blasters)

For many years, Ex-Marine Lieutenant Randolph and his troupe have put on a play aboard his ship. Having lost his family to pirates, Randolph wishes to put on plays that will give courage to those who have also lost their loved ones to pirates. Unfortunately, Randolph must retire soon, and he is now giving his last performance. Luffy and his crew come to see the play, and somehow manage to take part in it themselves. But from Randolph's past comes a vengeful subordinate with a diabolical plan who has finally become commander in order to capture Randolph. Luffy and his nakama now must prove to the people that not all pirates are scum, and protect Randolph's final farewell performance from the bitter commander. (aired after Episode 174) (Source: ANN)

After returning from the feuding realms of Gundalia and Neathia, Danma Kuusou and his companions continue their lives on Earth. Now, a year later, the virtual reality world of Bakugan Interspace has finally recovered from the alien invasion and has once again become a place for brawlers to gather and challenge themselves. It turns out, however, that whenever Danma's Bakugan, Pyrus Dragonoid, unleashes his might in battle, the Interspace experiences new disruptions. Unable to harness the incredible powers granted to him by Code Eve—the Bakugan Mother spirit—he struggles to maintain control over the Mechtogan contained within him. When it goes out of control, the mysterious mechanical entity wreaks havoc on the battlefield, attacking friends and foes alike. To make matters worse, Bakugan Interspace is at risk of being infiltrated again. An unknown mastermind is sending mutated Chaos Bakugan into the system in order to brainwash brawlers and take control of the virtual realm. In anticipation of the inevitable confrontation, Danma must find a way to keep the Mechtogan's destructive force at bay and rally the Battle Brawlers once again. [Written by MAL Rewrite]