Walknal-S

Warukunaru-S is an item which Run bought via the Galactic Courier, for using it to Lala. Its name "Warukunaru" means to become bad. It looks an ordinary spray, but nothing more than having a drawn face. This spray serves to change the personality of a good or pure person to sadistic, evil or perverted.

This spray is only able to be used one time and temporary in effect.

Plot
Run wanted to use it to Lala in the chapter 140 of To Love-Ru, for making Lala evil and Rito will hate her, but just when she was going to throw it to Lala, the Principal appeares wanting Run photograph her own body, but then she seemed to be surprised and accidentarily gave out the gas to Haruna, and Haruna seemed to change her personality.