If you want an anime with a calm main character, you can refer to the following works: 1 Death Note-The protagonist, Yagami Tsuki, has the ability to kill from the beginning, but she has always been very calm and does not show too much emotional fluctuations. 2 " Black's Basketball "-The protagonist, Black, was not a basketball player at first, but he became a top player step by step through hard work and calm attitude. Attack on Titan-The protagonist, Allen, is very calm from the beginning. He has been solving problems through his own thoughts and actions. Demon Slayer-The protagonist, Onishi Tsuji, is very powerful from the beginning, but he is also very calm and has been using techniques and tactics to deal with the enemy. 5 Sword Art Online-The protagonist Kirito was one of the strongest warriors in the game world from the beginning, but he kept his calm and rationality and did not let the game world get to his head.