In the Paris kara Kita Koibito series (パリから来た恋人シリーズ):

** Vol 1) Ai wa Kyouhaku ni Nite **
(愛は脅迫に似て; The Marriage Deal):

A husband's price...

Sandrine hadn't forgotten the thrilling passion she'd shared with her husband. But when, only six months after their wedding, Michel Nanier had forced her to chose between her career and their marriage ... Sandrine had to walk away. Michel had won her heart, but he couldn't rule her life!

Now Sandrine's career was facing a crisis, and only Michel could help her. He would do so, but for a price: Sandrine must agree to share her husband's life, and his bed, once more!

** Vol 2) Furimukeba Itsumo **
(振り向けばいつも; The Husband Assignment):

When Stephanie accepted an assignment to publicize a major film, she found herself having to negotiate with Raoul Lanier, the powerful heir to a billionaire empire -- and a ruthlessly sexy man....

Stephanie simply had to stop fantasizing about Raoul. It was his BUSINESS expertise she must concentrate on, not his bedroom technique! After all, they had a financial deal to settle. But then it became clear that the only merger Raoul had in mind was marriage!