I spent two days in Jugong with my mother.
Location is excellent, just a 3-4 minutes walk needed from guesthouse to Eef beach.
The room looked a bit old, but clean and comfortable. Washing machine was provided for guests to do laundry.
More importantly, staffs there were extremely helpful and patient! My Japanese was not fluent, they still try their best to make me understand. They helped me book Hate no Hama tour and called a taxi whenever I want.
The only problem is, if you can't drive, like me, you may have to spend extra to call a taxi to the guest house since there's only about 6 buses a day in Kumejima
I recommend Jugong if you're planning a trip to Kumejima.