Birdy uses her pin-up alter ego to help Tsutomu make a love connection with Sayaka, but everything goes horribly wrong when a Federation marionette is added to the equation! (Source: FUNimation) This OVA connects the first and second Birdy the Mighty Decode seasons.

Following the Ryunka disaster, Tokyo is left in a period of social turmoil. To make matters worse, the group of aliens directly responsible for the catastrophic event have escaped from the Space Federation and are hiding on Earth. Still sharing a body, Space Federation officer Birdy Cephon Altera, and high schooler, Tsutomu Senkawa, are tasked with capturing the fugitives and bringing them to justice. However, an unexpected crisis develops when the outlaws become targets of an unknown assassin with a vendetta. Now Birdy must deal with the chaos of everyday life and also uncover the identity of the assassin before more escapees fall victim.

The story takes place in the far future, when the civilization has declined. Hiyoko is a high school girl, who aims to enter an art university. She runs away from her home because her father tried to throw away her mother's keepsake drawings. She finds a slum located in a stadium and meets the leader of the street children, Akira. The police attempts to demolish the stadium for the beautification of the city. In order to resist the demolition, the people in the stadium plans to hold a street-art event The Asylum Session. Hiroko takes the charge of a giant painting on the stadium.

Forty-four years ago, the surviving nations of the Valbanil War declared peace and forbade the use of the devastating demon contracts that ravaged the land. Now, inexperienced knight Cecily Cambell is eager to follow the example of her family and protect the people of the city using the sword she inherited from her father. Her first challenge arises in the market. A crazed swordsman wreaks havoc upon civilians and Cecily jumps into action to restore order. Overwhelmed, her weapon shatters, but a skilled stranger wielding a strange-looking sword intervenes. With the situation diffused, Cecily heads to a local blacksmith in an effort to restore her family heirloom. However, she finds out that her savior—the blacksmith Luke Ainsworth—may be the only person capable of such intricate repairs. Determined to have her treasured sword repaired, she seeks out the man who rescued her. However, a group of bandits suddenly attack a convoy headed for the city. The assailants look inhuman, and an ice demon appears. Luke suspects the use of a demon contract and calls upon a sacred power to defeat them. Meanwhile, a shadowy hooded figure lurks, watching from a distance. Who is this mysterious evildoer, and what does his appearance mean for the pair?