According to GA Bunko official blog, adult PC game Otome wa Boku ni Koishiteru 2 ~Futari no Elder
was announced to get an anime adaptation. The first season Otome wa Boku ni Koishiteru
was aired in 2006. The story of Otoboku2 takes place two years after Mizuho
graduated from the school.
Otoboku2 official website
Source: GA Bunko blog