Till We Meet Again on the Lily Hill

Yuri is a high school student in the present day. She isn't happy with her life at home or school. One day, she has an argument with her mother and runs away from home. Somehow, when Yuri later opens her eyes, she realizes that she is in the year 1945. She happens to meet Akira, a pilot for a kamikaze unit in the military.
(Source: AsianWiki)
~~ Adapted from the novel "Ano Hana ga Saku Oka de, Kimi to mata Deaetara" (あの花が咲く丘で、君とまた出会えたら。) by Shiomi Natsue (汐見夏衛).