There’s an Asian cultural tradition of taking off one’s shoes when coming into a house. For Japanese students, that also applies when they go to school.
As students come into the entrance of a school, they are greeted with a lobby area that houses several rows of multiple cubbyholes. These cubbyholes are assigned to each student. They take out their indoor shoes from the cubbyhole and switch it with their outdoor shoes until they leave for the day or go to gym class.
Indoor shoes are white canvas slip-on shoes with rubber grips on the bottom. For elementary students, the rubber soles are color coded according to the grade level the pupil is currently enrolled. Colors may be blue, red, green, and yellow or whatever the school has set as the student grade colors. Elementary students also have to write their name on the top of their shoe. Whether this color system or name placement is used for middle and high school students, I haven’t found any data to ascertain this but it’s possible.
These shoes are washable and are supposed to be washed each weekend and taken back to school the following Monday. They are required for school and are considered part of a students uniform and school supply.
Indoor shoes and outdoor shoes may be interchanged several times a day; coming to school, gym class, recess, and going back home. There is also a separate shoe used specifically for the bathroom which is available just outside of the restrooms. Students have to put these on to use the toilet and take them off when they are done.
I’ve seen some of these indoor school shoes in Japanese stores here in America. If you would like your own set, it’s more than possible to get your hands on a pair, that is, if they have your size.