Why can't my emojis be seen?

My boyfriend got an iphone 5c today and I have the iphone 5. I can see his emojis that he sends to me but he can't see the ones I send to him? Why is this and how can I fix it?

Not sure. But thank for giving me the opportunity to look up what emojis are. I didn't realize what that meant.

… Is the Japanese term for the ideograms or smileys used in Japanese electronic messages and webpages…

Maybe he needs updates to his phone?

Ask Siri.