Travel To Another World: I'm The Only One Left

"Is this a dream? This must be a dream, right?" Chen Fan quickly took out his phone and dialed his friends. 
However, no one answered! The bad feeling in his heart became stronger and stronger. He then rushed out of his house, only to discover that the entire world was empty.
Chen Fan was no stranger to being forgotten and left out. As if he had been cursed, his sense of existence was so thin and easy to ignore. He got forgotten when he went on a vacation. He got left in the cafe when he went out with friends. He was even forgotten by the teachers all his school years, and no teachers ever called him out!
But this was not acceptable! Everyone else in the world had disappeared, but he was the only one left?
"Hey!!! I'm still here!"