Spin-off: 2D-kun Special (外伝 二次元くんスペシャル Gaiden: Nijigen-kun Special ) is a spin-off volume of the Golden Time light novel series. It was released on June 10, 2012.
- Chapter 1: Mr. Two Dimensions Special
- Chapter 2: Love from Mr. Two Dimensions
- Chapter 3: The Nijigen Incident
- Chapter 4: Farewell, Mr. Two Dimensions