KosaToge

KosaToge is a Femslash ship between Kosaki Onodera and Chitoge Kirisaki in the Nisekoi series.

Canon
Both are very close on each other, their relationship has been formed since their childhood, when Kosaki and Chitoge (as six-year old girls) met and befriended each other.

Some major point on the manga canon has invoked their closeness. As example of
 * 1) Chapter 69: Kosaki and Chitoge made their Valentine Chocolates together, although the valentine chocolate are intended for Raku, not for each other.
 * 2) more data incoming, stay tuned

Trivia

 * On the Nisekoi Audio Drama that comes with "Recovery Decoration" single, Chitoge is been heard gushing and loudly asked Kosaki to sing her song again.