Shounen ga Otona ni Natta Natsu – Episode 1 (RAW)

Orphaned young Ryuki Kirishima lives alone with his adored older sister Reiko, whom he idolizes as the greatest person in his world. One hot summer day, he and friends gather in their secret warehouse hideout to watch trending adult videos. While past content failed to excite him, the debut of sensational new streamer "Kiriru-sama" changes everything—her soft, massive breasts, flawless curvaceous waist, and overwhelmingly sensual hips leave Ryuki aroused for the first time. Obsessed, he fixates on her streams. Shockingly, the naked Kiriru-sama suddenly materializes in the real world before him. Revealed connections and hidden identities lead to intimate, forbidden moments that blur fantasy and reality. As summer heat intensifies, Ryuki's innocent admiration for Reiko collides with raw lust inspired by Kiriru, setting the stage for a secretive, transformative season filled with taboo pleasure and emotional awakening. This first episode teases deeper mysteries between the two captivating "big sisters" and the boy's irreversible journey into manhood.