Katsushika Hokusai titled his sketchbook series Hokusai Manga starting in 1814: man, whimsical or involuntary, ga, pictures. Drawings that wandered. Rakuten Kitazawa carried the word into modern newspaper cartooning in the 1900s, and the industry kept the master's joke as its name.
The story museums love: in a 12th-century handscroll, the Choju-jinbutsu-giga, ink-drawn rabbits, frogs, and monkeys act out a court satire, sumo-wrestling, praying, thieving. Scroll unrolls right to left, scene follows scene, and someone always calls it Japan's first manga. A comic seven centuries before the word existed.
The claim: manga is ukiyo-e reincarnated, the floating-world pictures of actors and beauties that Edo censors kept suppressing, reborn as the mass image industry. On this reading, comics are Buddhist picture-preaching, etoki, scaled to printing presses, and the sermon never stopped, it just changed gods.
If one artist's sketchbook habit became the world's biggest comics industry, which of your habits is a genre waiting for a name?