Dragon Quest Monsters J - Japanese Mobile Phones
Dragon Quest Monsters J for play on Japanese mobile phones.
The 2002 mobile phone game made by EZweb was called one of two names: Dragon Quest Monsters I (MOB) or "Dragon Quest Monsters J"
EZweb made two games, one with Gameboy Color graphics (the 2002 game) and one for newer phones in 2006 with updated graphics.
The 2002 version you could connect to a PS1 and trade monsters to the remakes of 1 and 2 and was the only way to get Ayebou/Aibou and Zoma's Devil on the remakes.
-- Info from captiveofchrist on the forums