Lines can be freely varied in thickness, and lines with characteristics such as “stops”, “flicks”, and “sweeping strokes” can be written easily, even with a felt-tip pen, marker pen, or the like. Moreover, a pen-tip does not readily become damaged or worn. A writing implement includes a shaft, an ink supply core such as that of a felt-tip pen or a marker pen, and a core surrounding member that covers the ink supply core. The writing implement is formed capable of contacting a tip of the ink supply core and a tip of the core surrounding member against a writing surface at the same time by using a joint capable of changing a relative positional relationship between the ink supply core and the core surrounding member.