Golden Time Gaiden: Nijigen-kun Special
ゴールデンタイム外伝 二次元くんスペシャル
Nijigen is a freshman and Banri's friend. He gains his nickname at the tea ceremony club's welcoming party after declaring his despair of the three-dimensional world and that he would live for the two-dimensional world from then on. His nickname in high school was "Satoutaka".