You'll find it right after you pass through the ticket gates. It's nice that they even have cushions!
The Kakogawa Line is a local line with only one or two trains per hour during the day. Furthermore, it has unmanned stations without automatic ticket gates, so you could sit on the benches on the platform if you wanted to. But, please remember the rule: you should only enter the ticket gates when you are using a train.
The operating hours are from the first train to the last train, but it doesn't seem like there are any shutters at the station entrance, so you could technically use the benches all day. Although, I doubt anyone would be using the benches in the middle of the night...





