Protagonist of the manga and anime series Demon Slayer: Kimetsu no Yaiba. The kanji used to spell his name give it the meaning of "coal + calm son," which describe his former profession as a coal worker.

Doting parents have begun to use names like Precious and Treasure, which are sweet for a baby, but might not hold up over the years. Treasure was used for nearly 300 baby girls in one recent year.