Kakure Tsuki (2000)

Kakure Tsuki is a visual novel released in 2000 for PC.

Storyline

The protagonist "Sakuya" is a being created by magic, awakening in Japan's magical research institute. His creator Shizuma Kusakabe tells him that he will spend 91 days in the mansion learning skills and interacting with different people and that he will be tested to see what growth he achieves.