Shojo sometimes dabbles with history, usually for the sake of reincarnation drama or the concept of star-crossed lovers. In this case, the creator of Yona of the Dawn looked at it and said "why not both?"
NG LIFE (NG Raifu), by Mizuho Kusanagi. First published in 2005 and first published in North America in 2009.
Nearly two millennia ago, the gladiator Sirex pledged to his lady love Serena that would return to her even as their hometown of Pompeii was consumed by Mount Vesuvius. Centuries later, Sirex has been reborn as Keidai, an ordinary Japanese teen boy. While many of the people around him are also reincarnations of people from Sirex's life, only Keidai can clearly remember that past. That makes things awkward when Keidai recognizes his beloved Serena in Yuuya, the grumpy boy who just moved in next door. Keidai isn't sure whether to convince Yuuya of their past connection or try to forge some new relationships in the modern world?