A thermochromic writing instrument including a writing body, storing a thermochromic ink therein, stored in a barrel; an operation body provided in the barrel to be operated to longitudinally move the writing body; a nib of the writing body configured to be capable of appearing from a front end of the writing instrument, wherein the writing instrument 1 further includes a friction unit, for rubbing handwriting in the thermochromic ink and capable of thermally changing the color of the handwriting by frictional heat generated at that time, and at least one clip body as the operation body, the friction unit 10 is provided at a rear end of the barrel, and the clip body is provided in an area other than the rear end of the barrel.

A stylus includes a casing comprising an opening, a push rod disposed in the casing, a pen head fixed on an end of the push rod, a reflector coupled to the push rod, and a linkage mechanism disposed in the casing. At least a part of the pen head is exposed of the casing. An end of the linkage mechanism is fixed on the casing. The linkage mechanism connects reflector to the push rod, such that when the pen head is pushed into the casing, a moving distance of the reflector is greater than that of the pen head, and the reflector is exposed of the opening.

A card shaped pen (13) with retractable pen tips designed to be stored in the card slot of a wallet, purse, and other credit card or business card holders. The shape is optimized to make it easy to slide in and out of a card slot and to make it comfortable for a user to hold. Each of the pen tips (7) have their own ink cartridge and sliding switches, enabling the use of multiple colors in the pen. Each pen tip is extended and retracted using its sliding switch (1), which locks in the fully open and fully closed positions. Thus a versatile pen is providedthat can be conveniently carried on person every day.

A card shaped pen (13) with retractable pen tips designed to be stored in the card slot of a wallet, purse, and other credit card or business card holders. The shape is optimized to make it easy to slide in and out of a card slot and to make it comfortable for a user to hold. Each of the pen tips (7) have their own ink cartridge and sliding switches, enabling the use of multiple colors in the pen. Each pen tip is extended and retracted using its sliding switch (1), which locks in the fully open and fully closed positions. Thus a versatile pen is providedthat can be conveniently carried on person every day.

A card shaped pen (13) with retractable pen tips designed to be stored in the card slot of a wallet, purse, and other credit card or business card holders. The shape is optimized to make it easy to slide in and out of a card slot and to make it comfortable for a user to hold. Each of the pen tips (7) have their own ink cartridge and sliding switches, enabling the use of multiple colors in the pen. Each pen tip is extended and retracted using its sliding switch (1), which locks in the fully open and fully closed positions. Thus a versatile pen is providedthat can be conveniently carried on person every day.

A card shaped pen (13) with retractable pen tips designed to be stored in the card slot of a wallet, purse, and other credit card or business card holders. The shape is optimized to make it easy to slide in and out of a card slot and to make it comfortable for a user to hold. Each of the pen tips (7) have their own ink cartridge and sliding switches, enabling the use of multiple colors in the pen. Each pen tip is extended and retracted using its sliding switch (1), which locks in the fully open and fully closed positions. Thus a versatile pen is providedthat can be conveniently carried on person every day.