If you've made your way to this guide, odds are you've beaten the Genichiro Ashina boss fight in Sekiro: Shadows Die Twice. Well done! After you defeat this boss character, you'll be reunited with the Divine Heir, Kuro. After speaking with him, he'll set you the task of finding and speaking with Lord Isshin Ashina. He gives some directions of where to go and what to do, but it's all pretty vague. In this guide, we'll talk you through finding the right location to talk to Lord Isshin.
Sekiro: Shadows Die Twice - How to find the right tower and Lord Isshin Ashina
To progress the story and the game in Sekiro, you'll need to locate Lord Isshin. Kuro, the young lord you're sworn to protect, gives you a rough idea, but in typical From Software style, it's not particularly helpful.
He'll tell you to follow the pink smoke signals you'll find all across the rooftops of the Ashina Castle area. You could systematically visit every smoke and eventually find him, but this not only takes up time, but could wind up in some pointless deaths thanks to the Nightjar ninjas. Instead, we're going to tell you exactly where to go.
Kuro suggests using the window behind him to get out onto the rooftops. Open the window and jump out, then turn to your right. You should see two towers of similar height right next to each other, both with smoke signals. Go to the one on the right, and you should find Lord Isshin sat inside. Easy!
What if he's not in the tower?
If he's not in the tower, don't panic -- you've simply missed a minor quest from earlier on. You'll need to finish it before Lord Isshin Ashina will appear in his place in the aforementioned tower.
Go to the Ashina Castle Gate Sculptor's Idol, and cross the battlefield to head up the steps on the other side. In the building on the right, you'll find a character with a mask on. Speak to him and he'll ask you to get rid of some "rats" near the castle. He's referring to a certain group of enemies near the Ashina Castle Gate Sculptor's Idol.
Go back to the Idol and carry on up the path. Kill the enemy around the corner and grapple up to the top of the gateway. To your right is a group of enemies on a raised platform, and you can eavesdrop on them. These baddies are the short fellows who wear large hats. They're pretty tricky to deal with, as their hats block a lot of your attacks. The trick is to use the Loaded Axe to dramatically lower their posture.
Once you've cleared this area, go back and talk to the same character. After this interaction is done, you should be able to follow the above steps to find Lord Isshin in his tower.