To provide a writing utensil set so convenient that a holograph with a writing utensil is constituted not to be visually judged by a colored transparent sheet and the holograph can be easily erased when unnecessary and writing can be performed again with the writing utensil to the erased portion of the holograph.

This thermochromism writing utensil set is formed by dispersing in a vehicle a microcapsulated pigment comprising a reversible thermochromism composition consisting of (α) an electron donative colorable organic compound, (β) an electron acceptive compound and (γ) a reacting medium controlling the color reaction between (α) and (β) and changes color from a colored state to a colorless state, and comprises a writing utensil housing a reversible thermochromism ink having the microcapsulated pigment under its colored state and the colored transparent sheet under the condition that the hue shown by the ink is the same color as the hue of the sheet or the colored hue shown by the ink is included in the structural color obtained by subtractive color blending of the hue of the sheet.