Wife by Agreement(2003)

Itsuwari no Kekkon Yubiwa

"Hannah, will you marry me?" The proposal from Ethan, a man she loves, should have been the happiest moment of her life... If the marriage wasn't just a contract. Hannah was hired as a nanny after Ethan's wife passed away, then Ethan asks her to be "a mother to his children." Hannah wants to be loved as a woman, but it seems Ethan cannot forget about his late wife... When will he realize Hannah's true feelings?

(Source: Jmanga)