Identification: What's this plant ?

I live in Tokyo, Japan.

I was given a plant, and I have grown the plant which is called "Oporubio" or "Madagasucariensis" locally, but, it's quite unsure.
As I attach some actual pictures I took, can I have the correct name and some related information ? Some local people here say its origin is Madagascar.

Thanks.

Sumio Namikawa

 

Looks like Euphorbia leuconeura, Madagascar Jewel.

 

Thanks a lot.
My question was finally solved!

 

http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=6784

You might find the above thread of interest.
A deep dive in Google suggests that the plant can get 4-5 feet tall.

 

Yes, I could refer to the informative pictures and comments on those websites with thanks.