The game - MobileWonderGate - WonderSwan | WS

The main unit allows the WonderSwan console to be connected to a mobile phone via an auxiliary port. A separate cartridge contained an email client and browser with HTML 3.2 support and the ability to download 32 KB mini-games. Some games, such as Digimon Adventure 02: D1 Tamers, allowed features to be added via downloadable content.

Internet connectivity was provided by the NTEP Docomo mopera (Mobile Operation Radio Assistant) service and J-Phone compatible phones.