Will this memory fit into my MacBook Pro? I'm planning to upgrade my MacBook Pro with another 4GB memory.
How do I know which memory is compatible with my MacBook?

I got MacBook Pro model A1278, processor 2.3 GHZ Intel Core i5, current memory 4GB 1333 MHz DDR3. Would this memory fit into my hardware?
I have here two helpful Links for you:

Apple Support Serial Number &amp;
Apple Support Memory Upgrade

I don't have experience with this memory, but i think it should work ;) But please use the provided Links and double check everything. I don't know how it is in Jp but in Europe you can send the RAM back to Amazon if it does not work. "Normally" a wrong RAM is not warming you Macbook. 

I hope this will help you and sorry if we can't provide for every RAM Module Experience ;)