In one embodiment, a magnetic head slider includes a write head having a single magnetic pole, the single magnetic pole having a main magnetic pole piece that extends to a medium opposing surface facing a magnetic disk. The main magnetic pole piece generates a recording magnetic field from a medium opposing surface side end face thereof being divided into an injection region and a non-injection region. Impurities which deteriorate magnetic properties are present in a higher concentration in the injection region relative to a concentration of the impurities in the non-injection region due to injection of the impurities in the injection region. The non-injection region has a narrower width at a leading end of the medium opposing surface side end face than at a trailing end of the medium opposing surface side end face. In another embodiment, the magnetic head slider may be incorporated into a system including a magnetic recording medium, at least one magnetic head, and a control unit coupled to the magnetic head.