Yes, when someone does an injustice to another person then some form of restitution or reparation is needed. When we do something wrong against another person and don’t seek forgiveness from Allah and them, then if Allah does not punish us in this world He will make us account in the next. Thus, we should ask forgiveness immediately and seek to repair our mistake. On the other hand, Kaffarah is offered by a person who breaks certain laws that Allah has made (like breaking fast without a valid reason).