While the anime does use music to enhance emotional moments, there are no specific, dedicated tracks for these particular scenes. The music you might be remembering is likely a combination of the following:
* General Romantic Themes: The One Piece soundtrack frequently uses romantic or love-themed music, especially when showcasing feelings between characters. It's likely that you're thinking of a piece that falls into this general category.
* Hancock's Theme: Boa Hancock does have her own recurring musical theme that plays when she's on screen. It often has a strong and seductive quality.
* Luffy's Theme: Luffy also has a recurring musical theme that's often associated with his determination and strength.
* Emotional Moments: The soundtrack uses music to amplify the emotional impact of various scenes, including those where Hancock's feelings for Luffy become clearer.
Unfortunately, without the specific episode or scene you're referencing, it's difficult to pin down the exact music you're looking for.
If you can remember the episode number or a specific visual clue, it might be easier to identify the track.