One of the Twelve Kizuki, a direct subordinate of Muzan Kibutsuji, is here somewhere. When Tanjiro slays the Mother Spider Demon of Mt. Natagumo, he learns that a demon who might hold the key to turning Nezuko back into a human is somewhere in this very forest. With the battered Inosuke in tow, he heads deeper into the forest. Meanwhile, Zenitsu trudges forlornly through the woods only to encounter a spider with a human face.
Season: 1
Sea God of the East, Azure Sea of the West – Reminiscence Chapter
Reviewing King En and Atsuyu's story provides a thoughtful Queen Kei with more to consider in governing her own kingdom. En delights Youko and Rakushun when he tells them Rakushun is to be at her side from now on as friend and protector.
Sea God of the East, Azure Sea of the West – Final Chapter
Atsuyu reveals his true nature to the court and in the face of condemnation admits defeat, but fails even then to be honest. King En promises a land of green meadows and fruitfulness to all his subjects.
Sea God of the East, Azure Sea of the West – Chapter Three
Trying to escape, Enji finds Atsuyu's father imprisoned and starving – though unable to die as he's an immortal sen-nin – by his own usurping son, and realises that his trust in Atsuyu is misplaced.