ANNA & ANNA is the story of Anna (Karena Lam) who seems to have everything in life, from love to career, until her boss decides to post her to China. There, Anna meets her ex-boyfriend, Ouyang (Lu Yi) and his wife, Si-Yu (Karena Lam) who looks exactly like her and later turns out to be her doppelganger. Love for her ex-beau rekindles and Anna decides to switch identities with Si-Yu for a week. Si-Yu then flies to Singapore where she falls in love with Billy (Tender), Anna’s current boyfriend. Realising that Ouyang is no longer the man she used to love, Anna desperately wants her old life back, but her doppelganger has plans of her own too.