Dangerous oni lurk outside, so you must never leave the mansion." Raised under the protective wing of your loving father, you’ve always heeded these words and stayed safe inside. Life in the mansion may be comfortable, but you wish that you could experience the outside world just once. One day, your wish comes true, but with a huge twist. The mansion suddenly comes under attack and you’re abducted by three handsome oni. What they want is the Hallowed Treasure, a legendary gemstone that was lost 20 years ago - yet you’ve never even heard of it.