Angered by Rui's death, Muzan kills the Lower Ranks due to their constant failures; he spares Lower One Enmu and tasks him with killing Tanjiro. After a battle against Enmu in a passenger train, Tanjiro kills him with Kyojuro's support. However, Upper Three Akaza appears and battles Kyojuro, who dies from his wounds as the demon escapes. Months later, the group is sent to Yoshiwara with Tengen, where they face off and kill the Upper Six siblings Gyutaro and Daki. Tengen retires from the Corps after suffering extensive injuries. During another battle at the Swordsmith Village, where the Corps' weapons are forged, Tanjiro meets Sanemi's younger brother Genya, who has the mysterious ability to temporarily gain demonic powers after eating their flesh. With the help of Muichiro and Mitsuri, the group kill Upper Five Gyokko and Upper Four Hantengu. In the aftermath, they discover that Nezuko is immune to sunlight. She becomes Muzan's prime target as he has long sought a way to overcome the sun and become immortal. Tanjiro also learns his Hinokami Kagura descends from "Sun Breathing", the first Breathing Style created by Yoriichi Tsugikuni, the most powerful Demon Slayer in history, and develops it to fight Muzan.