Kyosuke enters high school dreaming of a sparkling, youthful experience. One day, he reunites with his older childhood friend, Kyoko—once a reserved and introverted girl—who invites him to join the “Pattern Games Club.” The club is an intellectual and surprisingly refined activity group where high school students revisit classic childhood games like “playing house” and “hide-and-seek.” However, for some reason, unexpected incidents keep occurring, and their innocent games gradually take on a more complicated and emotionally charged atmosphere…!? These boys and girls only want to have wholesome fun, yet through reenacting children’s games, their relationships slowly grow more intense and morally ambiguous… Playing childhood games at this age turns out to be surprisingly thrilling and entertaining! An immoral youth comedy begins!