Rinne no Lagrange, Vividred Operation Recommendations
Girls operating robots to save the world from space invaders. Both have a bright feel to them with lead characters who are very eager to help people without care for their own safety.
Similar premise of a genki girl living on an island in the future. She likes to help people, and when their town is suddenly attacked by alien robots, she steps up to save everyone.
Both series features science fiction themes involving young girls fighting against enemies to protect what they treasure.
Both series' main female protagonist have similar personalities. They both like to help others, wishes to protect what they value, and are generally energetic and able to brighten anyone's day.
Both series features a lighthearted school setting where there is comedy, drama, and some tension.
Both series has action and some fan service during fight scenes.
Both series main characters' days are changed forever after the incident where the alien invaders enter their lives.