Blue

Blue (アオイロ, Aoiro) is the ninetieth chapter of the Nisekoi manga series written and illustrated by Naoshi Komi, and published weekly in the magazine Weekly Shōnen Jump.

Summary
The chapter continues off when Marika finds a children's book. Chitoge asks to look at it, and they notice that the title is scratched off. Kosaki recognizes the book, and says she hasn't seen it since she was little, and Chitoge recognizes the phrase "Zawsze in love" in the book, as well as locks and keys in the chapter.

As they examine the book, Raku comes in the room, and feels like he can remember something when he looks at the book. They find that whenever Raku looks at his pendant, the girls' keys or the picture book, it makes him remember the image of a girl. Chitoge then explains the promise she made ten years ago to Tsugumi, Shū and Ruri.

Chitoge recalls that her mother told her that she copied her ribbon from a girl in a storybook. The story in the book tells of a prince and a princess who fall in love. However, their kingdoms go to war, and they are separated. On their last day together, the prince and the princess make a promise that the prince will hold the lock, and the princess will hold the key. When they meet again, they'll unlock the pendant, gather its contents and live happily ever after.

After being separated, the prince runs to see the princess. He travels a long distance, and when he gets to a big door, another girl with a key unlocks it for him. The story shows the prince being helped by many girls with keys. However, the rest of the pages have been ripped out, so the gang can not finish the story.

The amnesiac Raku thinks that it was a sad ending, and recalls changing the ending for a girl because it made her sad. Chitoge and Raku leave to go look for the same book at Chitoge's house. At the same time Ruri is surprised that Raku was connected with the other girls by the keys and the story. At the same time as that, Shū follows Marika, and asks what she's hiding. Marika denies hiding anything and leaves.

As Raku arrives at Chitoge's house, he notices decorations everywhere. Chitoge mentions it's her birthday and that he forgot. Raku promises to get his memories back so he'll remember her birthday, after which she asks what he would think if she was his promised girl. Raku tells her she couldn't be the promised girl, since the promised girl did not have blue eyes.

Character Revelations

 * Marika and Chitoge recognize the picture book from when they were younger.
 * Kosaki owns the picture book connecting to the promise from 10 years ago.
 * The story book contains pendants and keys, similar to what Raku and the three girls with keys have.
 * This is the first time Ruri and Tsunami ever hear about the special promise.
 * The promised girl's eyes were not blue.
 * Raku has changed the ending of the story in the picture book.