Ashina: The Red Witch

These are the NPCs in Shiruta you need to talk to in order to unlock this achievement:

1. Tanto - in the sushi restaurant you start in
2. Kanu - you'll talk to her automatically after talking to Tanto
3. Kappo - he's inside the house in the lower right hand corner of the map. He'll give you the boom box
4. Roku - in the house at the bottom center of the map.
5. Chomin - in the house at the bottom center of the map. He's upstairs and will offer you speakers in trade for sushi
6. Trix - in the house at the lower level hand corner of the map
7. Gus - runs the ramen stand immediately next to the sushi restaurant
8. Hoji - in the tattoo shop directly above the ramen stand. You have to directly talk to him after the introductory cut scene to get credit for talking to him
9. Oakie - in the house at the upper right hand corner of the map. Talk to him after talking to Trix and he'll give you the Tasty Bun
10. Mogab - click on the floating S book next to the bridge at the top center of the map. I'm actually not sure if he counts towards the achievement but it couldn't hurt