Harukanaru Toki no Naka de 4 Aizouban

In Harukanaru Toki no Naka de 4, follows Chihiro Ashihara, one of two princesses of a kingdom locatrd in a land called Nakatsu Kuni within the parallel world. During her childhood, the kingdom was invaded by forces led by the king of Tokoyo no Kuni, a distant rival land connected to her kingdom. As Nakatsu Kuni is quickly overwhelmed, a divine power sends the protagonist through space-time to the modern world, protecting her from her kingdom's slaughter and ruin. Five years have passed since the massacre and the protagonist has suppressed her memories of her true origins. She believes she has been raised in the modern world and enjoys her peaceful life as an average high school student. Yet a mysterious encounter she has after school soon forces her to remember her true past and birthright. Returning to her home world, the protagonist is determined to save her people and resurrect her dying kingdom.