Mecha are self-propelling machines that are modeled after humans; some can change into multiple, non-humanoid formats as well. They're usually controlled by an internal pilot or by remote, but are sometimes sentient beings that move autonomously. A mecha's size ranges from bulky, wearable armor to a massive, towering contraption and beyond. While mecha have a wide range of applications, such as making manual labor easier, they are most commonly portrayed as heavily-armed war machines.
A reverse harem includes three or more characters who potentially show romantic interest in a female protagonist. The sex, gender, or orientation of the harem members is irrelevant as long as they exclusively, or at least primarily, are vying for the affections of the same individual - who may or may not reciprocate towards one, several, or none of these romantic rivals.
These anime delve into the world of competitive Sports, ranging from team-based to individual participants. From Baseball or Basketball, to track and field or combat-based sports, these works focus on the athletes and those around them who show their support.