"No." Ren firmly refused. He couldn't and didn't want to involve Nishino in matters like this.
As long as a genomancer didn't encounter a very strong monster, there was still a chance for them to survive. However, involving oneself in fighting the Blue Triangle was different. Once discovered, your fate was almost certainly sealed.
"Don't be quick to refuse. I'm not forcing her to join; I just want you to explain our situation to her and invite her. Whether she agrees or not is her choice," Hina quickly explained.
Ren thought for a moment. He knew that if he explained his situation to Nishino, including the bomb implanted in his chest, Nishino would help him. But that wasn't what Ren wanted. What he wanted was for the girl to remain uninvolved so that she would at least be safe from Kizuna's scrutiny.