Yuuichi Aizawa is the main character in Kanon. He's friendly and sociable but hasn't yet learned how sensitive women are. Throughout the story, he teases the female characters with varying severity. Despite this, he has a softer side that makes him seem like an older brother to Shiori Misaka. Although Yuuichi used to visit the city where the story takes place, his memories of it have faded and come back as he interacts with people from his past. He's afraid of heights, but this doesn't stop him from trying to help those close to him. As a normal person, he tries to protect them in any way possible, even if it means going out of his way. When Yuuichi discovers supernatural events happening in the city, he remains strong and helps his friends as much as he can.
Eventually, Yuuichi falls in love with and shares a kiss with Ayu.