If you are stuck at completing the Tidal Flats Puzzle then here is the solution. You will come across this puzzle during the Sacred Sakura Cleansing Ritual quest. This requires you to find a K-Shaped Ward first to unlock the next barrier. If you fail to find this you will not unlock the puzzle. Later you will have to solve the Barrier Puzzle Sequence to finally complete Tidal Flats Puzzle.
Genshin Impact Tidal Flats Puzzle Solution
To solve the Tidal Flats Puzzle go to Kamisato Estate. Use Memento Lens to observe a statuette of the Earth Kitsune. A third fox large statue will reveal itself in the middle. Hit it with Electro to get Key-Shaped Ward. It is nothing but a key that will give you access to the main puzzle.
Travel to the Tidal Flat island on the North-East of Kamisato Estate. Refer to the image to reach the exact spot, look for some fox statues. They are all pointing to a smaller one in between the mountain gaps. Look at the small statue with Memento Lens. This will reveal a secret opening down into the rocks. The end of this new cave opening has the final piece of Tidal Flat Puzzle.
If you remember Cut A Deal With Village Chief Mission has a similar puzzle where you just have to arrange the shapes in the right number. Use the Key-Shaped Ward to purify the lantern. There are around 5 lanterns in the area. Each has multiple comma-type symbols on them. You will have to adjust the order in a way that it unlocks a boss fight. Following is the answer to Tidal Flats Puzzle.
Follow the above pattern to solve the Tidal Flat Puzzle. This completes Complete the Sacred Sakura Cleaning Ritual. After solving all three pieces of the puzzle you will have to defeat two Ochimusha. You will get 60 Primogem and 5 Heroes Wit. You will also earn some 50K Mora and 8 Mystic Enchantment Ore.