Scar

Scar (キズアト, Kizuato) is the twenty-first chapter of the Nisekoi manga series written and illustrated by Naoshi Komi, published weekly in the magazine Weekly Shōnen Jump.

Summary
Chitoge discovers her old diary in the closet. Upon looking in it, she notices diary entries when she was 5 years old, the year Tsugumi said she met her first love. One of the entries include being attacked by a big dog and a boy saving her. The boy suffered an injury on his forehead but she nursed him back to health. Several entries after include how they played together and saving her whenever she cried, like the time she fell into a hole. The final entry was making a promise with the boy before she got on a plane with her father. She turns the page only to be blank. She holds up the diary where she finds a key that falls out of it. Chitoge asks Tsugumi, who was hanging outside her window, to make preparations to go to the place she met her first love, but forgets her class had an outdoor trip the next day. On the day of the outdoor trip, Chitoge is grouped with Tsugumi, Raku, Shū, Ruri and Kosaki.

At the destination, the teacher ordered all groups to make curry. Raku jumps at this chance to get Kosaki and Chitoge to do errands so he can cook the curry himself. Deep in thought about the boy from ten years ago, Chitoge accidentally spills hot water over Raku's head. As Raku moves his hand over his head, he exposes a scar, indicating that he might be the boy Chitoge made a promise with ten years ago. At the same moment, Raku notices the key hanging from Chitoge's neck.

Character Revelations

 * Chitoge has a diary about the adventures she had with the boy she made the promised to.
 * Chitoge lived in Japan for a certain amount of time and had met the boy she made her promised to in Japan.
 * Chitoge was attacked by a big dog and gets her ankle twisted but is saved by the boy. The boy ends up getting an injury. Chitoge stays with him until he was healed.
 * Chitoge falls into a hole but is once again saved by the boy.
 * Chitoge has a key that may be connected to the boy she made the promise to.
 * Raku has a scar on the his forehead.

Trivia

 * This chapter was adapted into episodes for Happiness (episode) and Hot Springs (episode).