Iago teaches Japanese language and culture through common situations and a visual novel story with funny characters, such as SephirothSword57, Sanic the Hedgehog, Akatsuki from Akatsuki Blitzkampf, and more. The game contains tips about cultural nuances, spaced repetition system practice, and conversation simulation. The reader takes the role of a nameless girl who has just moved to Osaka, Japan, where she meets the girl Iako-chan and her pet bird Iago. The two help her get used to speaking in Japan. If the player begins the story from zero Japanese knowledge, they will learn kana and other fundamentals through solving a locked-room murder mystery. As the player progresses, they receive coins they can use to unlock stamps, which each has a unique design and description about a real location in Japan.