Emoji Mush is 'Mushroom'(collaborative input app). You can input Emojis with this app. Note: Emojis do not appear to some phones. How to use Mushrooms. me/blog/use_mushroom (Japanese). Japanese IME to work with Mushrooms. Simeji. ATOK. OpenWnn. ‐ Google Japanese Input. POBox. POBox is preinstalled in Xperia series for Japan.