Insecurelycute's activites

I wanted to believe that natsune and yamabiki are still alive but what was their reason for leaving him behind on the bench if their reason are merely to travel that's too selfish bc they knew I'e was so worried of them, at least they talk to him again after the long time. And if they were dead then who wrote that next to him that doesn't make sense... Or maybe one of natsune escape and then happened to see i'e.... But im surely hope they WILL meet again in the future (me trying to cope) :')