Chuuya for Dazai is the main light of his life.that way Hoshikawa draws skk in different ways: Dazai is fully dark,like a shadow;Chuuya is pictured in bright colors. Chuuya suddenly burst into his life, he really interested Dazai so much. Chuuya treated him like an ordinary boy, not a prodigy demon. he reacted emotionally to Dazai's jokes and actions, Chuuya literally made his life much more interesting. made Dazai continue to live. And the way Hoshikawa draws Dazai's burning eyes when he is next to Chuuya😭 even Dazai-Rui's actor perfectly conveys his bewitched eyes.