EVERY TIME WE TOUCH, I HEAR THAT SOUND

Touji is an average high school student who is terrible at dealing with people and struggles with physical contact. On one rainy day, all of Touji's struggles come to a head when he encounters Itsuki Yato, a fellow classmate who touches him casually even when they first meet. Even though Touji isn't great at socializing, Itsuki goes out of his way to talk to him and spend time with him. Gradually, Touji starts to want to learn more about Itsuki... (Source: Futekiya) Note: Includes three extra chapters. — Description from AniList community (anilist.co).