Zynga today launched its mobile social role-playing game Montopia for both iOS and Android devices; the company also revealed Ayakashi: Ghost Guild (another mobile social RPG) will soon be available on both platforms.

Both Montopia and Ayakashi were released as Japan-only titles in early 2012 by Zynga Japan. Montopia is a free-to-play card-collecting/monster-battle game where players journey across the eponymous land and seek to figure out what happened to it. As they progress, the players fill a “Monstapedia” of creatures they find and fuse together to increase their attributes. Ayakashi, meanwhile, tells the story of exorcists investigating the mystery of some powerful legendary creatures called the Ayakashi. Players battle and capture ghosts, turning them into friendly demons (called Shikigami) they can use to fight against rival exorcists.

Mobile games using card-collecting and monster battles have proved incredibly lucrative in recent months, even here in North America. Mobage’s Rage of Bahamut regularly dominating the charts of top-grossing apps for both Android and iTunes. As was the case with many developers making mobile games in Japan, Zynga was affected by the recent ban of kompu gacha mechanics.