Shinnosuke Tachikawa is a college student involved in various hustling activities with his partner, Yuuga Ohta. Together, they distribute SCM devices and participate in the slave trading game. Their strategy focuses on gathering other SCM users, defeating them through tactical mind games, and turning the defeated into slaves. This partnership is central to their activities within the game's framework. Later, Shinnosuke participates directly in the high-stakes duels central to the SCM system. His role remains primarily linked to his collaborative partnership with Yuuga in navigating and manipulating the game's mechanics.