Climbing up and down the endless cliffs and steep hills of Watatsumi Island, you might encounter an oni-like emblem inked on the rock. You might have also noticed this same mark while completing the puzzle quest in the Seiraimaru Ship while on Seirai Island.
These are the markings of Rinzou, a pirate who lived a pretty epic life of treasure-gathering and adventuring before burying his loot for his men to find. But now the loot can be yours.
To trigger the quest, go to the cave below:
In the cave by the water are basic vegetables and trinkets along with a sparkling journal. Read the journal. Once done, you can actively seek out any inked markings on the cliff and dig as instructed. There are four locations total, plus one Treasure Hoarder camp. Each location rewards you with a Common Chest.
For quick reference, here are the locations of the marks and Rinzou’s cave:
Technically, you can run up from the cave Rinzou’s journal was found in. But there’s a great deal of time-consuming climbing and running around to do if you choose that route. It’s easiest to run off the cliff from the Statue of Seven and glide.
As you get closer, there’s an Electro barrier by the water. You don’t need to get through it to dig. Just go around!
Head East of the Statue of Seven and drop off the cliff. In between the coral, towards the ground and water, is the marking. It’s a bit hard to see but generally you can find any of the locations if there are wagons, wood and digging supplies on the ground close by.
Like the other locations, climb up from the bottom of the coast or take the simple way and glide off South from the Teleport Waypoint. If you glide, turn the camera around and the marking should come into sight as you curve the cliff.
You get a nice clear view of where this marking is if you take off from the Teleport Waypoint and glide West at an angle. Of course, it’s perfectly alright to reach it from the coast on the ground or from the base of Sangonomiya Shrine. Do what’s most convenient for you!
At this location, you can dig but the Treasure Hoarders will have already gotten to it.
The Treasure Hoarder Camp
Head to the camp. It’s right between two waterfalls filled with Treasure Hoarders, tents and supplies, plus an Exquisite Chest. Beat all the enemies and open the chest to activate the last part of the quest.
You receive Rinzou’s Letter. In the letter, he mentions the cave as the true spot he buried his treasure in. Go back to the southern cave where the quest began. Dig by his journal. A Precious Chest, Rinzou’s emblem, and a nice amount of reward are inside.
And there you go! Achievement and treasures earned.