Yoichiro Mikami wanted to be the next Masayoshi Son, Japan's second-richest man, so he dropped out of high school at 16 this year.
Now he's devoting all his time to Gnex Ltd., a crowdfunding firm backed by six sponsors, including Son's Yahoo Japan Inc. and the headhunting company Recruit Holdings Co.
Mikami's startup helps raise money for student projects, including an application that provides information for university entrance exams and a social network for students to share timetables.