I need a anime show like where some 1 changes there lifes forever?

like rorouni kensh trigun black cat somth with repentece or a show like where some 1 comes into a new place and helps ppl there abd channg there lifes forever like Air or Kenshin or somth like it Plz if u know 1 tell me but noth stuped like naruto or bleach pls thank u tell me as many as u know