The Ace Archer: Mount Oe quest sends Musashi to hunt five Kubi Akari spread across Mount Oe. Two sit along the main route through the Castle Courtyard and are easy to spot. The other three are tucked into the Futasegawa Mountain Stream, an area with no Spirit Mirror of its own, which is why the quest marker feels misleading when you try to fast travel there.
Quick answer: All five can be defeated in any order. Two are in the Castle Courtyard along the Mountain Trail, and the final three are in Futasegawa Mountain Stream, which you reach by fast traveling to Cave I and taking the cave path beside the shrine.
How to start Ace Archer: Mount Oe
The quest is handed out by an NPC in Shijo Street in Eastern Kyoto. Look for the man wearing a conical hat standing beside the grain baskets and talk to him. He mentions troubled souls lost at Mount Oe, and accepting begins the quest with the objective listed simply as Hunt the Kubi Akari at Mount Oe (0/5).
Completing the quest rewards Hempen Cloth x2, Leather x2, and Oni Stone x2. Kubi Akari themselves are floating Genma with a pale-blue tint; they puff up before firing energy blasts, so shoot them down cleanly with your bow rather than letting them react.
Kubi Akari 1 and 2 in the Castle Courtyard
Fast travel to Mount Oe from a Spirit Mirror, then choose the Mountain Trail Spirit Mirror. Both of the first targets sit along the route from here toward the quest marker.
Kubi Akari 1 above the tree-lined path
From the Mountain Trail Spirit Mirror, follow the track with trees on both sides toward the marker. Keep glancing up as you clear the Genma along the way. The first Kubi Akari floats above the path among the trees, and it is easy to miss if you are focused on ground enemies. Once you have a clear line, aim your bow and shoot it down (1/5).
Kubi Akari 2 above the wooden fort rooftop
Continue along the path toward the second marker, fighting through more Genma and archers on the elevated walkways. Climb the ladders to reach higher ground near the lookout tower. The second Kubi Akari hovers above a rooftop in this section.
The target can drift out of view depending on where you stand. If you lose sight of it, stay put and watch the area, and it will come back around, or move to find a fresh angle. Take the shot once you have a clean view (2/5).
How to reach the last three Kubi Akari
The final three targets live in Futasegawa Mountain Stream, which has no Spirit Mirror, so the map gives them no notebook icons until you are inside. The quest marker actually points at the area transition, not a fast travel point, which is what trips most players up.
Kubi Akari 3, 4 and 5 in Futasegawa Mountain Stream
Kubi Akari 3 under the bridge
Follow the marker for this target and watch for a yellow trail running along the mountainside. Use your Oni Power on the yellow trail and follow the route across the wooden planks. The third Kubi Akari is hidden under the bridge, so find an angle that gives you a clear line before firing (3/5). A nearby chest holds an Oni Stone if you want to grab it.
Hitotsume Gasa may harass you here. If they break your aim, clear them out first, then focus on the Kubi Akari.
Kubi Akari 4 above the raised platform
Keep moving along the route through Futasegawa Mountain Stream. You will soon hear the next Kubi Akari nearby. When you do, stop and look up toward the raised platform and the rocky cliffs above the walkway. The fourth target hovers there, so line up your bow and take the shot (4/5).
Kubi Akari 5 beside the stream
Continue past the fourth target and head down the ravine into the clearing, where flying Genma and swordsmen wait. The path opens onto a stream, and the last Kubi Akari floats at a distance beside the mountain. Find a spot where the Genma cannot interrupt you and shoot it to finish the hunt (5/5).
Report back to complete the quest
After the fifth target falls, the objective updates to Report back to the man. Travel back to Shijo Street in Eastern Kyoto and speak to the same NPC beside the rice baskets who gave you the quest. The Story Complete banner for Ace Archer: Mount Oe appears once you report in, and you receive the Hempen Cloth, Leather, and Oni Stone rewards.
