Shouka Kou serves as head of the Kou Clan among Saiunkoku's eight noble families and is father to Kou Shuurei. As the Kou family's eldest son, he was initially deemed unfit for leadership and expelled from the main household. He relocated to the capital, where younger brother Kou Reishin secured him a position as librarian of the Royal Archives—a low-paying yet respected role. Exposed early to the Kou Clan's power struggles, Shouka displayed exceptional biwa talent at age five. His great-aunt Kou Gyokukan noted witnessing clan conflicts had stripped him of childhood innocence. He later trained under the previous "Black Wolf," leader of the Wolves of the Wind—elite assassins serving Emperor Shi Senka—and succeeded her after her death. As the Black Wolf, Shouka commanded the Wolves of Wind under Senka's orders. His most consequential mission required assassinating his aunt Kou Gyokukan, who manipulated the Kou Clan toward ruin. He poisoned her tea and played the biwa during her final moments, an act that traumatized him into abandoning the instrument permanently. Shouka first encountered his wife Hyou Shoukun, the Hyou Clan's "Rose Princess," when assigned to assassinate her. Instead, he fell in love and proposed repeatedly until she accepted. They had one daughter, Shuurei. After Shoukun's premature death, Shouka raised Shuurei alone and took in exiled prince Shi Seiren (later Seiran) under Senka's protection order. Despite lethal capabilities, Shouka presents as a gentle, absent-minded librarian brewing notoriously bitter tea. Frequently sought for counsel, he turns ruthless when angered. His typically closed eyes reveal striking red irises with small pupils when open, signaling intensity. Years later, the Kou Clan initiated an embargo protesting Reishin's leadership. Shouka returned to Kou Province, forced Reishin's resignation as clan head, and assumed the position. Back in the capital, he publicly pledged the Kou Clan's loyalty to Emperor Shi Ryuuki, startling court officials with his open-eyed authority. Shouka's influence extends beyond his clan. The Ran Clan triplets (collectively Ran Setsuna) admired him as their childhood tutor, causing lasting friction with Reishin. His political involvement could sway the Ran Clan, though he generally avoids court affairs. In later years, he adopted Hyou Riou Jr. of the Hyou Clan and supported Shuurei as Saiunkoku's first female official. He retained the clan head position but concentrated on family and advisory roles, distancing himself from his assassin past.