Koe ga Dasenai Shoujo wa "Kanojo ga Yasashisugiru" to Omotteiru

声がだせない少女は「彼女がやさしすぎる」と思っている

The story of a mute transfer girl who uses a sketchbook to talk to people, and a bullish classmate with a special ability who befriends her. (Source: MangaDex)