日向坂46公式 ひなこい is a free iPhone game developed by 10ANTZ Inc. It is a unique communication RPG system that allows users to interact with the members of the famous Japanese idol group, Hinatazaka46. The game revolves around the story of a high school student who transfers to Hinatazaka high school and falls in love with one of the members of the group.

The game offers a new way of communicating with the members, where players can level up their relationship with their favorite members by answering their questions and eventually become their "kare-shi" or boyfriend. The game also offers a unique feature called "HINATALK," where players can communicate with the members through a game-exclusive communication app. Moreover, the game comes with a collection of exclusive content, including cards, movies, and voices of all the members. The game is free to download on the App Store and requires iOS 11 or later to run.