There are two important things to bear in mind regarding Japanese fashion. First is that, since so many people use public transportation, they almost always need some kind of a bag or backpack to carry their stuff in when they go out. Second, after spending all week wearing a mandated uniform or bland business suit, come the weekend, some people are overcome with the urge to express their individuality to the fullest with their clothing and accessory choices.
With that in mind, just about the fastest route away from your button-down Monday to Friday look is to slip on a backpack that’s the exact shape and size of a tiger’s head.