The first Yo-kai is Benkei. To find Benkei go to Blossom Heights and go to the bottom of Main Street. You will see a path that heads into the Sunshine Station area. Go up the path and at the end you will see a man. Turn right at the construction worker to enter the Springdale Underground Waterway.
The second Yo-kai is Quaken. To find Quaken go to Uptown Springdale and go all the way to the right side of the map. Once you are there go down the stairs ad you will find a tunnel you can crawl through. Go through the tunnel and you will find Quaken.
The third and final Yo-kai is Alhail. To find Alhail go to Breezy Hills. You will find stairs at the left side of the map. Go down the stairs until you get to a waterway. Go staight into the waterway and you will find Alhail.