A young boy Sora sits beside Shiro, his sister (not related by blood). Sora is charismatic and persuasive. And Shiro may be shy but her calculations are impeccable. They are inseparable and together they are Blank 『　　』. They are unbeatable hyper geniuses who have always won every game we have played.

"Hey, why don't you challenge us to a game... if you dare?" Sora smirks.