There is a theory that a kango (words of Chinese origin) 'manpitsu (漫筆)' meaning an essay which is 'writing (a sentence) at will' became 'manpitsu-ga (a picture painted at will)', then 'manga', also there is another theory that a type of spoonbill called 'mankaku (漫画)' which 'looks for various things' was the origin.
「気の向くままに（文章を）書く」という随筆を意味する漢語「漫筆」が「漫筆画」を経て「漫画」になったとする説と、「漫画（まんかく）」という名のヘラサギの一種から「種々の事物を漁る」意になったとする説がある。