In Japan, manga—the infamous nickname for Japanese Comics—is a great deal of business. It became a core industry which fringes include multi-billion merchandise and copyright business, and is seriously taken care of by the government. Outside Japan, manga, has been a secretively massive and growing industry. In Indonesia, manga was introduced by Elex Media Komputindo through the release of Doraemon, the all-time favorite manga. So far, the comics only succeeded to penetrate into the children and teenagers market. There is still a lot of potential for a market expansion. Noticing the potential, lately PT Elex Media Komputindo had taken the business more seriously, and started to execute the expansion strategy to adult market through the release of its brand extension, Level Comics. Level Comics concentrates on adult-oriented titles, which contains stories with complicated plot twists that requires further comprehension, a bit more violence and less sensors. It also takes a different physical shape than the existing comic books; bigger in dimension, richer cover and higher price. The question is, "Does the strategy really works, or turns into double edged-sword against Elex Media Computindo by providing contribution to company profit through eating its predecessor's market?" This research is designed to answer the question. Through a questionnaire which distributed to the consumer of comics with certain criterias, the research led us to a conclusion which shows the symptoms of brand cannibalism. It was due to the result of consumer's preferences which tends to favor the newly arising Level Comics and its more favorable attributes, and also several others discovery concerning the Indonesian Manga marketplace and its consumer behavior.