Deviluke, Lala Satalin

Princess of Deviluke. Ran away from home so she doesn't have to get married. Uses many self-made inventions. At first she was pretending to love Rito to keep from getting married, but eventually she fell in love with him. She has physical abilities far beyond that of a human and also has a distinctive tail coming from her back (which is very sensitive).

Being an alien, Lala has far more strength, power and speed than the average human. Her physical strength (without any inventions or powers) surpasses any human on Earth, and maybe even some aliens in the solar system. She has also shown slight durability even with her own tongue, like when she ate one of Run's really spicy sandwiches and it didn't even phase her.

She can fire laser beams from her tail. However, her tail is both her weapon and her weakness. On Planet Deviluke, females' tails are far more sensitive than males'. When someone touches Lala's tail, she becomes weak and seems to lose her strength, though she can shake anyone off of her tail with her astonishing strength.

Perhaps Lala's most distinguishing ability is being an extraordinary inventor. She is considered a genius and has made many inventions; however, Lala very much has the personality of both a perky child and an absent-minded scientist, resulting in all of her inventions being very toy-like, troublesome, and serving no important purpose besides fun, mischief, and unintentional fanservice. A running gag in the plot is that her inventions usually do not work as well as Lala and the others had hoped, often resulting into a perverted accident.

(Source: To LOVE-Ru Wikia)