Ienai Himitsu

Jenny, who cares for her aging mother by herself, ends up marrying Sebastian, a mature, wealthy businessman she happened to meet, out of convenience. As part of the agreement, she gets the child she's always dreamed of having via artificial insemination. And he gets the successor he's wanted so badly. Even if the marriage were to go sour for some reason, Jenny's still willing to give it a try to have her baby. But when Sebastian unexpectedly dies, she is visited by his son... who claims to be the father of her child!

(Source: Harlequin/SB Creative Corp.)