"I'm going to relive my first love with the older sister I've always admired." Kazari, an engineer at a VTuber production company, has an otaku-like personality and can talk endlessly about the things he likes, but at work he gets stuck for words and can't say a word, which has left him feeling troubled. At that time, he remembers Koto, a kind older girl from his neighborhood who used to practice speaking with him when he was in elementary school. Koto had died of an illness, and he thought he would never see her again... But in the spring 10 years after their eternal farewell, they have an unexpected reunion...!? A streaming romantic comedy that begins with a reunion with the older sister he admired as a child!