This dissertation examines the artworks of Unkoku Tōgan (1547–1618), an artist based in western Japan during the late sixteenth and early seventeenth centuries. Although Tōgan gained a reputation as an artist who inherited the legacy of Sesshū Tōyō (1420–1506), a celebrated master of ink painting, I aim to contribute a more comprehensive understanding of Tōgan’s oeuvre by examining it beyond this aspect alone. To this end, the study explores other dimensions of his career and paintings, with a particular focus on issues such as the role of patronage, the artist’s engagement with Chinese traditions, and cross-cultural elements related to Korea. I contend that the value of this thesis lies in its examination of Tōgan’s paintings through a lens that differs from those used in previous studies, thereby situating his works in a broader political and cultural context within East Asia. Chapter 1 focuses on the analysis of Tōgan’s stylistic development in relation to and beyond that of Sesshū, exploring Chinese artistic traditions associated with the formal attributes of Tōgan. First, I argue that the stylistic changes evident in Tōgan’s works between the sliding-door paintings at Buttūji in Hiroshima and Ōbaiin in Kyoto may have originated from his receipt of Sesshū’s "Long Landscape Scroll" from Mōri Terumoto, an influential daimyo based in western Japan, who employed Tōgan as his painter-in-residence. This finding suggests a revised timeline for the granting of the scroll to Togan; I thus propose that the event occurred between 1597 and 1598, which differs from the generally accepted 1593 timeframe. Nevertheless, even after this occurrence, Tōgan persisted in utilizing pictorial languages that did not align with those of Sesshū, which suggests that Tōgan developed distinctive stylistic approach. With regard to this matter, I elucidate upon the visual elements in relation to the Chinese models that were among Tōgan’s inspirations . Chapter 2 centers on the topic of patronage, examining the background on the lineage of Sesshū, synonymous with the outset of the Unkoku school, as well as the role of Tōgan and his artworks in assisting his patrons. It is accurate to note that previous studies have already addressed the fact that Tōgan’s patron, Terumoto, gave Sesshū’s "Long Landscape Scroll" to Tōgan, thereby reviving Sesshū’s artistic lineage. However, the statement has been presented in a cursory manner, without any detailed account of the circumstances surrounding the event. I argue that Terumoto, at a time when the Mōri were in a political predicament, formalized the artistic legacy with the objective of promoting the cultural authority and political legitimacy of the Mōri clan, in relation to the Ōuchi clan who were the most dominant hegemony in western Japan during the medieval period. This chapter thus intends to shed light on the circumstances and motivations behind the occasion, as well as to conduct a critical analysis of Tōgan’s contributions and the function of his paintings within the project. Chapter 3 offers an analysis of Tōgan’s Chinese figure paintings with an aim to clarify his relationship with the Kano school, with whom Tōgan is known to have trained, and of him as a man of culture. This chapter examines the thematic and stylistic associations with the Kano school, official painters serving the Toyotomi clan and the Tokugawa shogunate, affiliated with powerful elites in the capital. Despite Tōgan’s documented apprenticeship with the Kano school, it remains challenging to identify clear stylistic connections between his works and those of the Kano school, with the exception of a few examples, such as the landscape paintings of Buttsūji and the bird-and-flower screens in Tōshunji. In light of these considerations, I directed my attention to Tōgan’s Chinese figure paintings, which offer insights into this area. In my view, they appear to reflect a comparable approach to the Kano school in terms of their thematic choices and interpretations, which were likely tailored to cater to their military patrons with a political agenda. Moreover, previous studies have examined Tōgan’s status as a man of culture, but the majority of research has concentrated on his engagement with chanoyu, renga, and landscape paintings in the style of Chinese artists. To further illustrate this point, this dissertation took an alternative approach, investigating the unconventional iconography in his Chinese figure paintings, in relation to his familiarity with Chinese pictorial traditions and literature. Chapter 4 presents alternative research regarding Tōgan’s working environment and engagement with Korean culture, delving into his relationships with Korean paintings in Japan. While previous studies have identified some connections between Tōgan’s works and Korean paintings, the discussions were brief, typically comprising a paragraph or so, and lacked sufficient elaborations on the ideas involved. This chapter addresses this issue by situating Tōgan’s works within a broader regional context and undertaking a detailed examination of the ways in which they were shaped by the cultural and traditional heritage of their environment. In order to achieve this, this study takes into consideration various determinants that could have impacted Tōgan's artistic output. Such factors included the social circumstances in western Japan during his career, the perception of Korean painting in Japan, comparisons with Korean models related to the Mōri family, and inscriptions by Korean figures on his paintings. Furthermore, this chapter conducts an in-depth examination of one of his Bodhidharma paintings, which has not been the subject of comprehensive analysis within existing studies. I consider this an important painting because it bears inscriptions by a renowned Korean diplomat monk, Priest Songun, and a prominent Japanese diplomat monk, Keitetsu Genso. The painting therefore serves to reveal the actual connections and communications between a local Japanese and a legendary Korean monk who mediated with Tokugawa Ieyasu for reconciliation. With the newly proposed approach, this study aims to reach a new understanding of Tōgan’s paintings in a synthesized manner in relation to Korea. To summarize, Tōgan cultivated his own style by drawing upon a multitude of sources from the past and continental cultures and manipulated them in large formats, such as folding screens and sliding-door paintings. On the surface, he adapted his works to suit the needs of the new socio-political situation while decorating the residences of his patrons. At the same time, he was simultaneously striving to project his individual artistic identity as a man of learning from a warrior family. The multifaceted elements present in his artistic oeuvre mirror the dynamic era in which he was active.