Black Cat

Black Cat is a Japanese manga series written and illustrated by Yabuki Kentarō. Several characters from this series were used as inspirations for characters in the To LOVE-Ru series.

Plot
The story centers on a man named Train Heartnet who withdrew from an elite group of assassins called the Chronos Numbers and become an easygoing Sweeper (licensed bounty hunter) traveling with his partner Sven Vollfied and Eve.

List of To LOVE-Ru characters based on Black Cat characters

 * Yami - based on Eve.
 * Kuro - based on Train Heartnet.
 * Kirisaki Kyōko - based on character of the same name.
 * Tearju Lunatique - based on character of the same name.
 * Sephie Michaela Deviluke - based on Sephiria Arks

References in To LOVE-Ru

 * In Chapter 23, several characters go to sing karaoke at a place named "Kuro Neko", as in "Black Cat".
 * Chapter 61, Yami try several clothes in a store. One of these is Eve' main dress.
 * In Chapter 134, Lala plays a target shooting game while dressed as Train Heartnet, the protagonist of Black Cat, right down to using Train's "Hades" firearm and tattoo of the Roman numeral "XIII". And Yami is seen in the background of the same panel wearing the clothing of Eve.
 * The chapter titles for 149 and 150 in the manga where Kuro appears in are called "The Smiling Cat" and "The Determined Cat", respectively. These are directly lifted from episodes 4 and 5 of the Black Cat anime, respectively when Train goes to save Eve from weapons dealer Torneo Rudman.