The first episode will be bundled in the 24th volume of the Shingeki no Kyojin manga series, to be released on December 8, 2017, while the remaining two episodes will each be bundled in the 25th and 26th volumes, released on April 9 and August 9 of next year, respectively.
Amazon Japan, as well as various bookstores, have listed three OVA episodes of the Shingeki no Kyojin: Lost Girls spin-off novel on their website, revealing that the series will receive an anime adaptation.