[5] He attended Junior and Senior High School at Komaba, University of Tsukuba.
[6] He was part of the university team in the 2013 and 2015 International Collegiate Programming Contest which won third place both times.
[1] Soejima also attended the Graduate School of Information Science and Technology at The University of Tokyo.
[7] Soejima's other significant achievements in competitive programming include winning the 2011 Google Code Jam, winning the 2016 Facebook Hacker Cup, and being Topcoder Open Algorithm champion in 2010, 2011 and 2016.
[5][8][4] A more comprehensive list of achievements can be found at the Competitive Programming Hall Of Fame website.