Ryoshima Coast is an important hub area in Okami. It is very large so large that it is split into two places; Ryoshima Coast and North Ryoshima Coast. It is a coastal region and there are a lot of important places to travel in the ocean too which is very tricky if Amaterasu only can use the Water Lily Technique. Wedged between the two areas is Sei'an City. The Thunder Ear on Masu's Wanted List are found here.
 Ryoshima Coast
Ryoshima Coast is the first new area Amaterasu explores after she has defeated the Orochi and she must help Yoichi raise the bridge at City Checkpoint before she may do so. It is connected to City Checkpoint, Sei'an City and North Ryoshima Coast.
 Main Features
Ryoshima Coast has a lot of water features, both a long shoreline and a lake. It does not have as many islands as North Ryoshima Coast, only an island where the Dojo is found and a few other small islands which are really only clusters of rocks pointing out of the sea. However these islands have lots of Treasure containing Shells near them. It's main ocean feature is the Sunken Ship which lies half submerged right in the middle of the ocean in an area know as the Lunar Lagoon due to the giant crescent moon shape the coral reef makes. Looming over the Lunar Lagoon, is the Moon Turret which can make the waters recede if Crescent is used.
The sea is plagued by the Water Dragon so exploration is quite hard before it's death. You can explore by using Water Lily and even then using Galestorm to "sail" it, however this is quite time consuming. Using the Water Tablet is much faster but it cannot be obtained till defeating Oni Island.
Ryoshima Coast also has a wooded area filled with lots of Animals. In front of the forest is the area's Merchant.
On land it's most notable feature is Ankoku Temple and the giant bell outside it. It also contains a lake and a waterfall that are down in a large hole, there is a tall tower in the lake that can be climbed. The area's Guardian Sapling is on a plateau high about the temple, it is accessed by traveling through a cave with empty lakes. The lakes must be filled with water so that you can water the withered sapling before Blooming it. There is also a Devil Gate Trial Cave and two secret passages to Sei'an City and Agata Forest which become available later in the game.
There is a pier that juts into sea and beyond that there is the entrance to Sei'an City and North Ryoshima Coast. There is a Mermaid Spring at the locked entrance to North Ryoshima along with an Ultimate Origin Mirror, there is another Origin Mirror near the entrance to Ryoshima Coast itself.
 Side Quests
 North Ryoshima Coast
This area is a lot more busy than Ryoshima Coast, although it as not as big, and you can only access it after getting the Border Key from Queen Himiko. When you first enter it you are greeted by Waka who has informed you that he has already bloomed the area's Guardian Sapling.
North Ryoshima Coast has a lot more islands than Ryoshima Coast, these islands are also much larger and hold a lot more things of interest on them. The largest island holds Catcall Tower on it along with a lot of feedable cats. Two other islands hold Divine Springs which teach you the Secret Brush Techniques Power Slash 2 and Cherry Bomb 2. Some less exciting Islands are one that holds a Crystal Rock, another one with a Devil Gate Trial Cave on it and one where you can fish for a Marlin which earns you another secret Brush Technique. Oni Island also appears in the sea but you cannot access it without the help of the Water Dragon and it disappears after you have defeated Ninetails. The Dragon Palace is underneath the ocean but the whirlpool to travel there can be accessed by using Orca.
When the Water Dragon is still alive it is hard to use Water Lily to travel the ocean but after you talk to Urashima and meet Orca for the first time you can use him to travel around as he can out swim the dragon. You can continue riding him even after defeating Oni Island.
On land the most significant feature is Watcher's Cape, named after The Watcher who stands up there watching the stars. It is essentially a set of ruins lying on a cliff top which protrudes into the ocean. It is an important area later on in the game as Amaterasu needs to make the Whirlpool Galaxy appear in order to access the Dragon Palace.
Other important areas are Umi's Restaurant which is at the beach beside Watcher's Cape and if you bring him a Marlin you can learn Whirlwind. On the other side of the small bridge there is Urashima and his wife's house, by talking to him you can learn about the Dragon Palace. Clearing a Demon Gate makes a little girl appear and she will give you information about Catcall Tower. Other humans include Yoichi but he leaves as soon as you help him and the Merchant.
There is also a Rocky Area that can only be accessed using Mist Warp, it contains a Stray Bead.
 Side Quests
North Ryoshima Coast has quite a lot of sidequests. These include:
- Marlin Catching. If you catch a Marlin with the unnamed fisherman you can give it to Umi and this will cause Kazegami to appear and grant you Whirlwind.
- Fishing. The fisherman will continue to help you fish even after you have caught the Marlin.
- Target Practice with Yoichi. Helping Yoichi to smash the golden apple with his arrow will make him move onto Kamui
- Devil Gate Cave Trial. Beating this will earn you a Sun Fragment and a Stray Bead. Every other time after that you get a Golden Peach for defeating it.
- Urashima and the box. To do this you need to talk to Urashima after you have opened the whirlpool and after you have killed the Water Dragon. After this you can bloom the area of land where you entered the Water Dragon and a Treasure Chest will appear, giving this chest to Urashima earns you a Stray Bead and Praise.
- Secret Brush Techniques. Donating enough Yen to the Divine Spring will upgrade to either Power Slash 2 or Cherry Bomb 2 depending on the Spring
Ryoshima Coast reappears in Okamiden, however it has been renamed North Ryoshima Coast and South Ryoshima Coast. Chibiterasu first travels here when he gets washed up by the flood that Bullhead caused before his death. He must then clear the cursed zone and head for Sei'an City. Chibiterasu also goes back in time with Kurow in search of Sage Shrine. When he goes back in time, he goes back to the time before the Water Dragon attacked so he can also visit the Goryeo before it was sunk.
The area has, however, been changed quite a bit as a result of the debris and rubble caused by the return of the curse. South Ryoshima Coast has not changed much apart from the entrance to City Checkpoint being blocked off, as it does not appear in the game. The islands in the sea can be seen but are inaccessible due to the absence of the swimming mechanic in the game. Moon Turret appears but is badly battered and the tower in the lake near the original entrance is gone. The underground cave that once housed the Devil Gate Cave Trial reappears but does not have its former use. A pheasant can be found near the entrance to Sei'an City and he can be convinced to move to Yakushi Village.
North Ryoshima Coast has drastically changed. Most of the major landmarks are gone such as Catcall Tower and Umi's restaurant. All the houses and characters have also disappeared. Watcher's Cape can be seen in the distance but is unreachable. Instead the entrance to the Moon Tribe Ruins can be found, taking up most of the map. Sugawara's Grave can also be found located on a high up ledge near the entrance from South Ryoshima Coast. Eventually Akuro destroys the Moon Tribe Ruins so all that is left is their rubble.
- The two rocks in then middle of the ocean with a rope connected them is a reference to Meoto Iwa, the Loved one-and-loved one Rocks. These rocks can be found off the coast of Futami, Mie. They represent the marriage of Izanami and Izanagi and therefore celebrate all marriages.