mysql> show variables like "chara%";
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | latin1 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | latin1 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.04 sec)
単純にjson_encodeをやっている為の文字化けでした・・・orz
参考
https://qiita.com/toshihirock/items/fdbc8e7b889e0d17a18d