Google is hosting Hackathon in their office and other office. Feel free to join this project and use the resource here if you are the participants of the Hackathon google Japan hosts.
At first, please read the following documents.
Guildline of source code repository How to use this repository for OpenSocial Hackathon. (Japanese only) How to register your account to each SNS for OpenSocial Hackathon. (Japanese only)