Unlock this achievement by first opening the door that has "Comm" on it in Shi No Numa and then the door where the perk machine is located. There is a door on each side of the perk machine; go in the one on the right. As soon as you enter that door, take a left to find a black phone sitting on the table next to a radio. Go to the phone and hold [Reload]. You may need to do this a few times. You will start to hear numbers being dialed, it will start to ring, and the achievement will unlock.