Natsu no Arashi
Plot Summary: Yasaka Hajime meets a strange girl Arashiyama Sayako who turns out to be a ghost from WWII. They can "connect" and together travel back in time. Along their adventures they meet Kamigamo Jun and Kaya (also a ghost) whom can also connect and do time travel. 2 other ghosts from the same time, Yayoi and Kanako, drains Arashis existance so they can live. Hajime fights to save Arashi, but ends up connecting with Yayoi and traveling back in time with her as well.