RETRACTABLE BALLPOINT PEN

Provided is a thermochromic retractable ballpoint pen including a friction body at a rear end of a barrel for easy thermochromicity only in a desired area. A retractable ballpoint pen is characterized by that the pen includes a friction body, at a rear end of the barrel, used for friction of handwriting in the thermochromic ink, enabling thermochromism of the handwriting in the thermochromic ink with frictional heat produced at that time, and having rubber-like elasticity, a maximum outer diameter of the rear end of the barrel is from 1.0 times to 1.5 times a maximum outer diameter of the friction body, a maximum width in a circumferential direction of the operating portion is less than the maximum outer diameter of the friction body, and an angle of a tangent to both the friction body and the operating portion from a writing surface is 60 degrees or more when the friction body is downward and an axial line of the barrel is in a vertical state relative to the writing surface.