Story
Much of the damage attributed to "Vash" is caused by the activities of bounty hunters who are after the 60,000,000,000$$ (sixty billion "double dollars") reward on Vash's head for the destruction of a city called July. Vash does not clearly remember the destruction of July, and only wants "love and peace", as he puts it; though he is a gunfighter of inhuman skill, he uses his weapons only to save lives wherever he can.
Synopsis via AniList (English).
Preview
From the anime adaptation: Trigun.