Sono Kao de Aisanaide

Nora, who works as a maid in a wealthy estate, is having a secret love affair with Makoto, the young master. But one day, Makoto suddenly dies in a car accident. While Nora is overcome with grief, Makoto's twin brother, Nozomu—who had been adopted out as a child—suddenly appears before her. "Shall I become Makoto for you?" The same face. A different person. The heart wrenching love story of one girl and two twins.

(Source: Kodansha, translated)