Stratos 4 OVA (2004)

After successfully returning to Earth on the renovated Stratos 4, the four main characters are visited by the Comet Blasters Chizuru Kubo and Annette Kerry, who bring them a shocking video. Meanwhile, Orbital Station 7 is in serious trouble... This two-episode OVA comes between the first and second seasons. (Source: ANN, edited by Glenn Magus Harvey)