The fourth chapter of the Darwin's Game ~Flag Game~ novel.
The reason the man watched Kaname and Rein leave was because of a whim, and because he felt somewhat empathetic toward them. He could tell they were Darwin's Game players, and assumed they were pretending to be brother and sister to spy on them, though the latter was based on his intuition. Through years of experience killing others, the man could tell if people had killed, and he felt that from the two of them, especially from Kaname. At that point his eyes met Rein's, who'd looked back to check if they were being followed, and he knew that they'd most likely meet each other again because of the game.
In the Sunset Ravens building in southeast Shibuya, Shuka was sulking on her bed in her room on the topmost floor of the building. She had planned on going on a date with Kaname, however, he had left to check out the Black Lotus base with Rein. She was sulking because she didn't make plans beforehand, and because she was the one who suggested checking out the enemy base, knowing full well that she was too popular to go on reconnaissance. As she laid there, she received a message from Rein asking her if she knew who Fuli was. She replied that she didn't know, though she felt uneasy upon hearing the name. Not feeling sleepy anymore, she headed to the roof with her chain and disappeared into the night.
Although the Ravens had a proper meeting room, they usually discussed stuff in the recreation room, which was created by Maesaka Ryuuji and based off of a billiard bar. Ryuuji was usually the only one who used the room, unless he forced Kaname to come with him, and one corner of the room had been taken over by Sui and turned into a "children's room" where she placed her video game consoles and board games. Upon arriving, Rein noted that Shuka wasn't there, causing Sui, who was busy playing a video game, to mention that she was probably outside. Hearing this, Liu Xuelan stated that they should begin the meeting anyway, as they could tell Shuka the results of the meeting later. Despite being a member of their clan, Rein still didn't trust Xuelan, especially since she still hadn't revealed what her sigil was. In response to Xuelan's words, Kaname agreed that they should start the meeting, mentioning that he'd tell Shuka the details, and everyone present gathered at the bar counter.