Under normal circumstances, Japanese students don't change clothes in the classroom. In the school classroom, the locker room is usually a special place to change clothes, such as the locker room of a gymnasium or gym. Students usually change into sportswear or school uniforms in the locker room, and then go to the corresponding activities.

In Japanese school culture, attention is paid to keeping clean and respecting others' personal space. Therefore, in general, students will change clothes in the locker room or designated changing area, not in the classroom. This can keep the classroom clean and tidy, while respecting the privacy of other students.

Of course, for special circumstances, such as theatrical performances or other activities that require dressing, the school may provide corresponding dressing facilities or temporary dressing places. Under these circumstances, students will change clothes at designated places according to the arrangement of the school to maintain the overall order and respect.

It should be noted that different schools and schools may have some differences in grades, so the specific regulations and practices may be different. But generally speaking, changing clothes in the classroom is not a common practice.