Eternal zero - Naoki Hyakuta

At the 60th Anniversary of the End of World War II, sibling journalists Kentaro and Keiko are given an opportunity to research the death of their estranged grandfather. Apparently he may have been a Kamikaze bomber, but there is much more to his story than just his death. He was a plane builder who did not create his machines for war but developed this engine for high altitude and long distance as a tribute to the sky and to ingenuity. His story is one of family, love and pacifism in the skies above the Pacific.