Among the writings attributed to Ikkyū Sōjun, the work that stands at the center of his legacy is the *Kyōunshū* (狂雲集, often rendered “Crazy Cloud Anthology” or “Crazy Cloud Collection”). This collection gathers his verse—primarily in Chinese-style kanshi, along with some Japanese poems—and reveals the full range of his iconoclastic Zen, from sharp social criticism to reflections on impermanence and the rawness of human desire. It is widely regarded as the primary textual window into his thought and personality, preserving his distinctive blend of spiritual insight and unconventional expression. For anyone seeking to encounter Ikkyū’s voice directly, this anthology serves as the foundational text.

Alongside the *Kyōunshū*, the *Jikai-shū* (自戒集, “Collection of Self-Admonitions” or “Self-Admonishment Collection”) is also associated with Ikkyū’s name. This work presents verses and reflections in a more admonitory and moralizing tone, focusing on personal discipline and the corruption of religious institutions. Where the *Kyōunshū* often revels in paradox and provocation, the *Jikai-shū* turns that same clarity of vision toward ethical self-scrutiny and critique of monastic complacency. Together, these collections suggest a practitioner who refused to separate insight from responsibility, or poetry from the demands of practice.

Beyond these major compilations, various poems, sayings, letters, and sermons attributed to Ikkyū have been preserved in temple records and later anthologies. These fragments, though less systematically arranged, contribute to a more rounded picture of his life and teaching, revealing a Zen master who spoke as readily through spontaneous verse as through formal instruction. Traditional biographical chronicles and anecdotal collections, such as those that recount stories and episodes from his life, further illuminate how his contemporaries and successors remembered his character and conduct.

Modern scholarship and translation have also played a crucial role in shaping access to Ikkyū’s world. Works such as John Stevens’s *Wild Ways: Zen Poems of Ikkyu* and the studies and translations by Sonja Arntzen offer curated selections of his poetry along with interpretive framing that highlights his unorthodox spirituality. These efforts, together with other scholarly essays and translations, invite readers not only to appreciate Ikkyū as a historical figure, but also to encounter his poems as living expressions of Zen insight, still capable of unsettling complacency and awakening a more direct, unvarnished engagement with reality.