Limited Wardrobe applies when a character wears the same outfit constantly, regardless of the setting or season, despite it being non-mandatory as opposed to wearing a uniform.
Limited Wardrobe is a concept or trope that appears across all kinds of fiction including television, video games, cartoons, anime and manga. Characters appear to wear the same outfit for very long periods of time, even if they only appear to have one set of those clothes. This isn't limited to only one outfit, but generally speaking a character is shown in one outfit for a long period of time before changing to another outfit, either briefly or permanently. It should be noted that characters who are required to wear certain clothes, like students, teachers, doctors and so on, are generally exempt from this.
In anime and manga, this is most prevalent in shounen series, such as Pokémon or Dragon Ball. Characters very rarely change their wardrobe, and even when it's extremely hot or cold they will usually just shed a layer or add a coat or scarf. More notable exceptions to the rule include wearing swimsuits to go swimming, but such cases usually only last an episode/chapter or two before the character puts their usual outfit back on again.