Sleeping in Okayama station

I am going to travel from Hiroshima to Kyoto in March. I am going to use Seishun 18kippu this time. After checked the timetable of the trains, it seems I have to wait for the first train in Okayama station from 00.08 until 05.14. Is it possible for me to sleep in Okayama station? Or should I find some other places to stay only for 5 hours?

Thank you!

AFAIK all train stations close between the last and first trauns of the day, so you will need to find something else.

No, just most major stns closed by shutter or policeman checking regularly instead.
Real rural no stn staff stns possible easy but not recommend just safer than other countries.

Okayama is one of major stn closed every nights cannot stay any passage,stairs and extra spaces.
And in Mar still not warm not recommend if not u lived/experienced in snow country enough.

How about KIX?
http://www.sleepinginairports.net/2014/best-airports-asia.htm
http://www.kansai-airport.or.jp/en/access/index.html
http://www.kansai-airport.or.jp/en/resshop/index.html
By 18 kippu only from Hiroshima possible needs about 4h plus after Okayama.
But 4h plus means also reached Kyoto possible.