Kodansha is one of the worlds largest manga publishers and they have just lodged a complaint after Amazon Japan removed 1,000 titles from their their Kindle Unlimited platform. Kobunsha has also confirmed that 550 of their comics were also removed.
Amazon Kindle Unlimited launched in Japan on August 3rd 2016. The program costs ¥980 per month and users get access to over 120,000 Japanese titles and over 1.2 million in foreign languages.
There is some speculation on why Amazon has removed vast amounts of comics and manga from big time publishers. The Wall Street Journal reported that Amazon would pay publishers a year-end premium for every user that read up to 10% of an offered publication, in addition to regular fees. According to the their source, manga, magazines, and photo collections began disappearing from the service in mid-August. Meanwhile, The Japan Times stated Amazon told the publishers its budget ran out after some titles saw demand beyond what Amazon expected.