High school student Hayama Takashi falls in love at first sight with a girl named Oribe Azusa, and subsequently they start dating. One day, Azusa made an unusual confession to Takashi; everyone, including her family and friends, forget her existence a few hours after meeting her. Takashi doesn't believe what Azusa says at first, but by chance he realises it was true. Knowing this, he documents their time together in order not to forget her. What will happen next? (Source: yuukii at MyDramaList) Adapted from the novel "Wasurenai to Chikatta Boku ga Ita" (忘れないと誓ったぼくがいた) by Hirayama Mizuho (平山瑞穂).