The second season of Kidou Senshi Gundam Thunderbolt.

Seven months after the One Year War ended, the remnants of the Principality of Zeon reform as the Republic of Zeon and continue to battle. Daryl had piloted the mobile suit Psycho Zaku in the end of the war at the "Thunderbolt Sector," where the Moore Brotherhood's fleet was annihilated. After losing the Psycho Zaku, Daryl descends to Earth and takes up an intelligence position to gain information about the South Seas Alliance, a military group within the Earth Federation. Io, who faced off against Daryl, is selected to pilot the prototype mobile suit Atlas Gundam and heads toward Earth.

(Source: Anime News Network)