Touhou: Fading Illusion

They say curiosity killed the cat, but Yukari Yakumo didn't seem to know the saying. Her little experiment with the Hakurei Barrier had consequences that the youkai world was not prepared for. Gensokyo is shaken by a series of small and seemingly unrelated incidents, and eight groups of youkai and humans set out for investigation. None of them suspects what their actions might result in.