BIRDY THE MIGHTY DECODE: THE CIPHER

This OVA connects the first and second Tetsuwan Birdy DECODE seasons. 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) — Description from AniList community (anilist.co).