Soji has experienced the combined area of technology and law and has been an experienced patent attorney as well as an attorney. In 2002, he joined Hitachi, Ltd. where he worked on domestic and international patent prosecution, consulting, litigation, trial and the like, mainly in the electrical patent area. He passed the Patent Attorney Examination in Japan in 2003. He served patent consulting service which is patent strategy, prosecution, patent learning and more, in 2005. He attended Osaka Law School from 2005 to 2008. In 2009, he passed the Bar Examination and joined the Legal Training and Research Institute.

He joined Uchida & Samejima Law Firm in January 2011. He has worked on intellectual property litigation and strategic intellectual property advice to technology corporations.

In 2002, he graduated from Doshisha University, Electric and electronic engineering major (Bachelor of Engineering). In 2008, he graduated from Osaka Law School (Juris Doctor).