The phrase starts with , which acts as a declaration of the medium. Doujinshi are a massive subculture in Japan. Unlike commercial manga, these are sold at conventions like Comiket.
Itako (いた娘) might have been a mis-split of ita kodomo → ita ko + domo (pluralizing suffix).
is a popular platform for amateur and self-published Japanese manga, commonly known as doujinshi . One specific title gaining attention on the site is "Ninkatsu: Anata ni Nita Kodomo ga Umitakute" (妊活。～あなたに似た子供が産みたくて……～), created by artist Tachibana Roku and the group Rokusyoku Mikan .