This is a popular visual novel featuring artwork by IshiKei. It is an adult-oriented game (18+) that uses Live2D animation.
For fans of the Japanese artist Ai Otsuka, this is a dedicated mobile application. Available for free on the Google Play Store . Love Cube Free Download
The complete game is a paid title available on Steam. 2. Ai Otsuka Official Fan Club App "LOVE CUBE" This is a popular visual novel featuring artwork by IshiKei