
The story starts on September 11th, 2018. Hayato Hino is a high school student at Ryuusei Academy in Tokyo, and is a member of the school's Second Science Club. That day, he goes to the roof of the school to practice his "Dragon Unit", a flight pack. Just as he's about to test it out, he sees a girl falling out of the sky, wearing a similar device. He tries to save her, but fails and falls to his death. However, several seconds later, he finds himself having gone back in time a few seconds ago (though he has no memory of it) with the same incident occurring.
code_18 is a Japanese visual novel of 497,272 characters, with 14,485 unique words and 1,982 different kanji. Its difficulty rating on Jiten is average, 2.5 out of 5. The full vocabulary list ranks all 14,485 words by how often they appear, and you can study them on Jiten or download them as an Anki deck.
Here are some of the words that appear most often in this media, as well as a sample of its rarer vocabulary.