Warlords Of Sigrdrifa: Sakura Vol. 1 (Light Novel)

One day, an enemy called “Pillar” appears in the skies about Earth and humanity finds itself under attack. Suddenly, the god Odin appears and gives humanity a way to fight back: young females called Valkyries who pilot special, magically-enhanced planes called Hero Wings. Sakura Okita is a young girl who isn’t satisfied with sitting back and waiting for peace and decides to participate in the “First Valkyrie Selection Exam” in search of the power to fight back and make a difference. There, she meets Sonoka Watarai, an 11-year-old girl who aspires to become a Valkyrie. The two begin spending their days training to become Valkyries so they can realize their dreams. However, the time of destiny is drawing near as Ragnarok approaches in this prequel to the original series by Tappei Nagatsuki.
Notice: This light novel is written in Japanese.