Kourin, adopted into the Sa clan by Sa Enjun and Hyou Eiki, began as Kou Shuurei’s lady-in-waiting before marrying Tou Eigetsu. Her fierce loyalty to the Sa clan drove her to orchestrate a dual poisoning of herself and Shuurei after Shi Ryuuki refused Enjun’s granddaughter as an imperial consort—an act she deemed necessary to uphold the clan’s honor. Following Enjun’s demise, she retreated to Sa province with Hyou Eiki but later returned to the capital to deliver urgent warnings of rising regional tensions. During a voyage back to Sa province alongside Ensei Rō, Shi Seiran, Shuurei, and co-governors Eigetsu and Shuurei, Kourin was abducted in a case of mistaken identity. To dispel doubts about her true role, she replicated Mei Senshi’s famed poem, revealing her sharp intellect. This pivotal moment, combined with Eigetsu’s efforts, led to their escape to Kinka with aid from Sa Kokujun. Initially marked by mutual frustration and cautious concern, Kourin’s bond with Eigetsu deepened into romance. When his mystical connection to the entity Yōgetsu faded, Eigetsu openly declared his love, compelling her to stay in Sa province as his partner. After Yōgetsu’s hibernation, she dedicated herself to aiding Eigetsu’s governance. Trained in domestic arts under Hyou Eiki, Kourin balanced practicality with strategic insight, evidenced by her resourcefulness during captivity. Her journey from a conflicted Sa loyalist to a confident leader beside Eigetsu underscored her resilience amid political strife and personal transformation, defining her role in shaping the clan’s legacy.