This does not mean people somehow take their shoes off facing that direction from the start. If you step up into the house normally, your shoes will usually be left pointing toward the interior. After stepping inside, you turn around, straighten them, and point them back toward the exit.
The most obvious reason is practicality. If the shoes are already facing the door, they are easier to put on when leaving. You can step down from the raised floor and slip your feet into them without having to turn the shoes around again or awkwardly reposition yourself at the entrance.
But convenience is only part of the reason.
The genkan is the first part of the home people see, so shoes scattered around at different angles can make the entrance look untidy. If a guest leaves their shoes pointing into the house and lying crooked, some people may quietly think, “They could at least straighten them and turn them around.” It is not usually treated as a major offense, but arranging your shoes is seen as a small sign of consideration.
The opposite can also be true. If a guest has neatly lined up their shoes and turned them toward the door without being asked, the host may not say anything, but may think, “This person is really well-mannered,” or “They were brought up well.” It only takes a few seconds, yet that small action can suggest attentiveness and good manners. The positive impression can be surprisingly large compared with the effort involved.
Guests are not always expected to arrange everything perfectly themselves, either. After a guest steps inside, the host may straighten the shoes and turn them toward the exit. This keeps the entrance neat and also makes it easier for the guest to put them on when it is time to leave.
So turning shoes toward the door combines practical convenience with consideration for keeping the entrance orderly. And when a guest does it naturally on their own, it can create a quiet impression that they are thoughtful and well-mannered. In a Japanese entrance, that extra step after removing your shoes serves both practical and social purposes.
