Kinjirareta Futari Himitsu Darake no Koi

What kind of a trap has this man set for Sophie?
Sophie is an actress whose best friend, Jasper, wants her to pretend to be his girlfriend to hide the fact he’s gay. So, wearing a provocative outfit, she hurriedly hops on the train to get to Jasper’s father’s birthday. The attractive, sophisticated man sitting in front of her on the strain gives her a look of blatant contempt. The two happen to get off at the same station and, it turns out, are heading to the same destination. He’s Jasper’s brother! Believing that Sophie is only with his brother for his money and title, he decides to set a trap to reveal her true motive!

(Source: Harlequin)