When Chuuya from the IF Route Transmigrated into the Main Story

To Nakahara Chuuya, Dazai Osamu was both his closest friend and the boss he respected. Yet this man, who should have led the Port Mafia to prosperity, chose to kill himself, leaping from a high-rise and smashing his body to pieces. Chuuya wasn't surprised that Dazai had killed himself. He was just surprised that he really had smashed himself to pieces. There was no hint of a joke in it. He had truly rushed toward death, dying in a way that looked agonizing. "The former boss was an idiot." Chuuya often said that, then lowered his head to deal with paperwork. He angrily raised a hand as if to shove it away, but forced himself to bring it back and keep reading, all while grumbling about a certain irresponsible guy. "Tch, you sure went and died quickly! All you do is leave me with trouble!" It was driving him crazy! Dazai's death drove him crazy. So did the endless paperwork, the heavy burden of being the boss, and... the loneliness of being all alone. He kind of missed his closest friend. "Chuuya, look! I found something great, and he's just as short as you!" Dazai cheerfully draped a black coat over the shoulders of the boy beside him, teasing him with gleeful malice. "I'm being so considerate of you. I didn't give him a hat, I gave him a coat, so now you're not the shortest anymore! Oh, right, I heard newborn puppies make the first person they see their owner." Dazai reached over to scratch the boy's chin. "Good little puppy, from today on, you're my dog. That scary-looking person over there is the enemy! Just wait for me to give the word, then bite him to death!" Chuuya's face went blank. He punched him. "Drop dead!" Chuuya from the if timeline: "..." He was a little dazed to have suddenly transmigrated to another world, but he was happy to see the boss. Except his boss seemed a little off! Theme: Chuuya from the if timeline experiences the warmth of the main-timeline Dazai