Kimi to Ikirareru nara Shindemo Ii

Houri is living an extremely uneventful life when, as if drawn to his crosswalk, a truck nearly runs him over. A passing man saves him, and the moment he sees the man's face, Houri's eyes are filled with flashbacks of their past lives when they had been intimate. The two are led by extraordinary fate to make love, but the next morning, the man bluntly says he doesn't remember Houri...!? A story of a love that recurs, until death do they part.

(Source: Libre, translated)