HANI is a simulation game where you take care of Haniwa clay figures, helping them grow through five stages of development. Neglecting them may lead to them running away or breaking, but with proper care, they can become authentic Haniwa unearthed from Gunma Prefecture.

Feed your Haniwa their favorite foods like mirrors, magatama beads, and pottery shards obtained through excavation. Keep their rooms clean by flicking away dirt, pet them to increase their "friendship level," and engage in Haniwa quizzes to boost their knowledge level.

Excavate various Haniwa figures, including people, birds, horses, and cylindrical shapes, and visit museums to collect special Haniwa. Decorate your own ancient tumulus with the Haniwa you've nurtured and acquired from museums.