Enman Rikonsuru Hazu ga, Teiou to Yobareru Danna-sama wo Yuuwakushitara Hiru mo Yoru mo Aisaretemasu

Ayaha is a college student who's married to Masato, an elite attorney who has the nickname "emperor"... But they spend their married life apart, with her in Japan, while he lives in New York. The marriage is actually a contractual one, under the agreement that they would divorce right after Ayane's graduation. But Ayane wants to avoid getting divorced, so she resolves herself to dieting and succeeds, resulting in her transforming into a total knockout. When she then goes to New York to see Masato, he doesn't realize she's his wife, and starts passionately seducing her...?! Source: HarperCollins Japan