From Kuhombutsu station turn left, and walk straight til you get to the first traffic light. Take the left path (scenic route) straight all the way to the temple gates, take a left, and the 2nd building is the Okusawa Chiku Kaikan. Pictures below.
Once youve found the scenic path, walk to the end (maybe 1 minutes walk) and you'll see this gate. Turn left at the gate.
As soon as you turn left, and see this little path, the 2nd building on the left is the Okusawa Chiku Kaikan.