Based off Magical Nuko Len Len. Rin is a scientist who used her twin brother, Len, in her experiment. As a result, Len became a hero and Kaito will have to kiss him to become Kitty Len Len. But unfortunately for Len, he will have to face Queen Miku to save the city. However, there's some twist.... This story has yaoi and some yuri (at the future)... Also... this is my first yaoi fanfic... Warning: Some colorful language, Yaoi and might be nosebleed. Disclaimer: I don't own Vocaloid.