How to insert utf-8 mb4 character(emoji in ios5) in mysql?

I am using mysql 5.5.10, and its character_sets are

| character_set_client     | utf8mb4                    |
| character_set_connection | utf8mb4                    |
| character_set_database   | utf8mb4                    |
| character_set_filesystem | binary                     |
| character_set_results    | utf8mb4                    |
| character_set_server     | utf8mb4                    |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
| collation_connection     | utf8mb4_general_ci         |
| collation_database       | utf8mb4_general_ci         |
| collation_server         | utf8mb4_general_ci         |

I changed utf8mb4 from utf8 for iOS5's emoji. They are represented by 4byte code.

But when I inserted 3 smiley emojis, '???' is in mysql.

They are 3F 3F 3F (Hex).

I can store iOS4's emojis well, but not iOS5's.

How could I store iOS5's emojis?

Please help me.