Samantha "Sam" Manson is one of Danny's best friends. She is a very self-proclaimed goth (much to her parents' dismay) and a strict Ultra-Recyclo Vegetarian.; wearing dark clothing and unholding interest in the subliminal and netherworldly, but combines this with an outspoken attitude on vegetarianism, animal rights and environmentalism. Her personality is seemingly less dreary than the stereotypical "goth" persona usually shown. Based on how she conducts herself, it would be fairer to say that she labels herself a goth more as an outlet for her independence and individuality than as an embrace of how the stereotypical goth is presumed to behave-as such, she is often livid over the wider range of popular materials.
Her parents are extremely wealthy, having inherited from the great inventor of the deli toothpick cellophane-twirling device; although she keeps this a secret with only her two best friends knowing; she'd rather earn real friends instead of dealing with the popularity and fake friendships that come with wealth.
She has an often strained relationship with her folks due to their optimistic, colorful personality as opposed to her darker outlook on life.
Sam's got into her fair share of troubles and adventure (usually as a result from her indiviuality), ranging from being turned into a ghost dragon briefly when wearing the Amulet of Prince Aragon when Paulina, who wore it for a while, gave it back to Sam, thinking it was hers, to accidentally erasing Danny Phantom's existence by unknowingly making a wish Desiree grants to nearly being a bride to Prince Aragon and getting possessed by Undergrowth, a plant ghost, as his second in command. She is also responsible for designing Danny's new "DP" emblem which he has kept for the remainder of the series. She's known Tucker and Danny from since at least the 2nd grade.
For the case of her relationship with Danny, throughout the series they have developed crushes on each other, possibly blossoming into love. Their feelings (which neither one was brave enough to admit to for a long time) have sent both of them in emotional circles, as Sam is often left to watch Danny put a move on other girls--particularly Paulina, or at one point when she had a boyfriend herself, leading to awkward situations.
The issue was resolved between them during the climax of the series finale, "Phantom Planet", when Danny officially gives her the class ring and tells her that no matter what the future holds, he hopes she'll be there to share it with him.
Sam was appeared when Danny's world was takeover and disappear by been capture by the Orgs, she also briefly seen in epilogue of Chaos Emerald arc when Danny reunited with her and Tucker. Then later she along with Danny joined with the Society Top elite, hunting for an ancient artifact weapon that rumored the Dark king builded for safe keeping in Other fan story, Ultima: CLASSIFIED.