Nice beachside area and clean, probably better for Summer where you can enjoy a swim and use of its facilities including change room and shower. We just walked around as a train stopover and there wasn't too much else to see. There are jumping fish in the water which is a funny sight to see if you pass by. Some food shops open if you need a bite or drink but the stock standard stuff.
Beautiful place for a park and sleep. Unfortunately one side is only open to 10pm (which does not qualify as a Michi-no-eki). The other side of the rest station is wonderfully located on the beach. 3.5, could easily be 4-5 Star.
The only downside are the noise from local motorcycles making noise with their bikes (and I'm a biker too).
Solution, bikes must leave by latest 11pm. Otherwise, it's an amazing beach side park.
Futami seaside park is a beautiful destination. The beach is safe for swimming, and they provide showers, changing rooms, and free parking. I recommend enjoying your summer here.
Great roadside stop. Lots of great small local shops. Beach is really nice.