There is work to be done.
Ghost of Yotei will set you on the path of a vengeful samurai seeking her family’s killers. You’ll need to level up your gear to stand much of a chance against the enemies that await you. Different resources can be found in different parts of the world in Ghost of Yotei. If you need to get to Oshima Coast in a hurry, this is what you need to do.
How to get to Oshima Coast in Ghost of Yotei

If you have just started playing Ghost of Yotei, you may have discovered the Oshima Coast Gatehouse in the western portion of the Yotei Grasslands. This will be locked, and if you want to get past it, there is plenty of work to do first.
Getting to the Oshima Coast will require you to finish certain portions of the story. You’ll need to get into the second chapter of the story, which means you’ll want to take out The Oni in the Ishikari Plain and The Kitsune in Teshio Ridge. Next, do the Shogun of the North quest (you may need to finish The Way of the Dual Katana first), then venture home and meet Jubei.
After this, you can start to hunt down the Saito Brothers, starting Chapter 2, and this will set your mission marker to the Oshima Coast Gatehouse, allowing you to finally pass the guards there.
If you are looking for more helpful guides, be sure to check out our Ghost of Yotei page.
