This article defends the position of a certain type of libertarianism and explores the policy implications of basic income that are actively being discussed across the world, including in Japan. There are several types of libertarianism. In the genealogy of Nozick, self-ownership and the Lockean proviso are two cogs and wheels of such arguments. Libertarianism can take shape only as other argument supports the other. From this point of view, this paper examines in detail how Nozick has tried to defend self-ownership. His argument respects the separateness of persons in a certain way and attaches the importance to make it possible for people to freely design their own lives and live a meaningful life by themselves. In addition, after reviewing the nature of historical entitlement theory and the Lockean proviso, I will take up the interpretation of the Lockean proviso, which is a central theme in recent libertarianism. In this paper, I mainly consider the baseline of Nozick, sufficientarian interpretation and egalitarian interpretation. There are advantages to such a sufficientarian interpretation, derived not only from the adequacy of the theory as a distributive principle itself but also from the fact that (Nozickian) libertarianism bears a specific image (a person with self-ownership). Furthermore, this sufficientarian understanding provides a moral basis for free economic activity on markets, which libertarians regard as important, and it is different from divesting legitimate private property and redistributing it that libertarians reject. I define a simple and general basic income for theoritical purposes and for Japan. This paper ultimately concludes that basic income does not completely morally conform to the conception of sufficientarian libertarianism, despite its appeal, and I will defend a system such as guaranteed minimum income, though some difficult issues remain.