All of Joyama is tuff (from the Italian tufo) is a type of rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption.
BATTLE RUNNER (4P) 5.8, 5.10a, 5.7R, 5.9R Can be done in three pitches. The overhang is the crux. It's a good place to undercling. Just go straight up and over it.
The last pitch (about 40m) is easy but a bit run out.
South Face of Joyama. The start is the middle of several bolted routes. Homeboy 5.8 is five routes to the left and close to the obvious tree.
Sport climbing with bomber anchors at each pitch. You will see old, rusty unused protection as well.
First pitch of Battle Runner looking up.
part way up looking down
The roof section. Note old bolts.