This paper examines differences in conceptions of “realization” among four of Hōnen’s disciples, Ryūkan 隆寛, Shōkū 証空, Kōsai 幸西, and Shinran 親鸞. These four all emphasize the significance of faith in Other Power, and understand that the attainment of “realization” (shō 証) means either that practitioners reach the bodhisattva stage beyond the first abode (shojū 初住, eleventh stage), as in the perfect teaching (engyō 円教), or the first ground (shoji 初地, forty-first stage), as in the distinct teaching (bekkyō 別教), following the Tendai school’s doctrinal classification of the fifty-two stages of bodhisattva practice. Among these four masters, Ryūkan, Shōkū, and Shinran use the word ōjō 往生, which means “birth in the Pure Land,” also in the context of practitioners’ attainment of the stage of “realization” in the present life to demonstrate that practitioners can attain the state of “realization” in their present lives. All four teach that nembutsu practitioners who attain faith in Other Power are equally able to attain the stage of “realization” instantly at their birth in the Pure Land. However, only Shinran maintains that practitioners will reach the stage of wondrous awakening (myōgaku 妙覚), the stage of the attainment of buddhahood upon birth in the Pure Land. In contrast, Ryūkan, Shōkū, and Kōsai understand that those who attain birth in the Pure Land must continue to progress in practice to reach the stage of wonderous awakening. In conclusion, based on this analysis, this paper points out that in studying Shinran’s conception of realization, it is problematic to raise such questions as “Is birth attained in this present life or after one’s death?” or “Did Shinran teach birth in this present life?” based on an inaccurate assumption that the terms “realization,” “birth in the Pure Land,” and “buddhahood” simply refer to the same state.