Zero Woman Returns (1999)

Original title: Zero WOMAN　最後の指令

The World's Sexiest Agent Strikes Back

Rei, whose undercover role is so guarded that there is no written record of her identity, is well known for her accuracy in completing missions and her willingness to get naked if the situation calls for it. When she's instructed to bust Kayama, who has been buying confiscated drugs from corrupt police officers, she finds herself in a sticky situation -- not only is she attracted to him, but Kayama, like Rei, does not officially exist.