I must find this amazing garment.

According to the little boy trying to convince his sister to buy it, whatever she was trying on was perfect for playing War, Ninja, Ninja Detective, and Old Man and Old Woman, the last one seeming to  entail them dying at the end.  All that I can be sure of was that someone was going to be playing Ninja when he got home, and if his sister didn't buy whatever it was that she was trying on, she wouldn't be.