Don't leave

Sei's face was rigid but he couldn't hide the pain in his eyes as he watched Hinari. Watching her, Sei understood why Zaki firmly decided to hide this from her but Sei strongly believed that the decision he and Davi made was the best thing they could do for the two closest people to them. 

For many years, Sei didn't stop searching for something that could save Zaki and he kept on searching, even now. Sei believed that there was no reason for them to give up just yet. This was why for the first time, Sei chose to break his promise to Zaki. He wanted Hinari to stay with him and give him a reason to fight. He wanted Hinari to never give up on him and to make Zaki not to give up on himself.