Walk to the gate ahead and press V to use Eye Awakening, revealing two new "ropes".
The main road on the left is blocked by ropes, so head into the house on the left and collect any items inside.
You can see many Phantom Demons across from the house. Use the cart on the left to take out half of them.
After dealing with them, go to the small room on the right. Use Eye Awakening to reveal and kill the small spiders.
Then retrace your steps; the main road that was previously blocked is now passable.
Follow the main road to a residence and assassinate the Phantom Demon in the hallway.
Some doors on both sides of the hallway can be opened, containing materials you can collect.
After collecting the materials, enter a courtyard filled with enemies and defeat them all.
After defeating the enemies, follow the rope and crawl through the gap.
Once you crawl through, press V to eliminate the spiders.
Open the dropped treasure chest to obtain the Oni weapon "Dual Blades [Niten]".
It's simple to use: when the blue energy bar in the bottom-right corner is full, press G to release it instantly.
