Plant/seed from Ibusuki

Hello.
I bought a seed and a plant (the latter was thrown away before leaving Japan unfortunately) from a stand near Cape Nagasakibana in the Satsuma-peninsula area.

The plant I know the name for (through kanji on the photo of the sign I took), the seed however had no sign, just an example plant standing by it. The seed is 2-3 cm across, more like a persimon seed.

The seller said it would be better grown in warm weather or in a glasshouse.

Unfortunately the best source of information is a picture, might not be enough but please give it a try. Thanks in advance!

http://s30.postimg.org/p8g0iksz5/P6290332.jpg

(It's the light brown colored seeds, not the dark brown ones at the bottom.)

I'm not 100% sure, but it looks like Sotetsu (in Japanese) or Cycas revoluta.
http://en.m.wikipedia.org/wiki/Cycas_revoluta
http://www4.synapse.ne.jp/genzi/plants/cycas-j.html
They are found in Kyushu and Okinawa, so obviouly they need very warm-hot weather to grow.

Looks very alike, also when lookong at pictures of the seeds.

Apparently poisounous. Better be careful. The seeds themselves are rather dried out so I wonder if they are ever to grow.

But right now we are experiencing temperatures past 30 deg Celsius so for the moment probably Kyushu temps.

Thanks for your help!!