Sanwa Supply just released the simple & light Bluetooth 4.0 apt-X headset - Bluetooth Headset 400-HS033BK - for 5,980 yen.
The Bluetooth headset weights only 14g. It is compatible with iPhone5s/5c/5 and smartphones. It features an elastic flat cable not to not easily get entangled, and a microphone for hands-free call.
Communication distance: 10m
Cable length: 50cm
Power supply: built-in lithium-ion battery
Accessories: USB charging cable and ear pieces (small/medium/large)