Mao Xingyun has been a loner since birth, and it wasn't because he is bad at communicating(well at the start) but because whenever someone tries to get close to him, they suffer from bad luck. His life is full of misfortune, he's hated by his parents, he's ignored by children his age or worst prejudiced against but not to the point they bully him, because all that bullied him suffered from bad luck, which he's thankful for because that's the only good thing his circumstance brought to him.
(author's note: from what I google translated cat is Mao in chinese and lucky is Xingyun in chinese so i picked Mao Xingyun as my mc's name, just comment if you think I'm wrong, I ain't chinese lol so sorry)
Mao Xingyun always felt lonely so when a black kitten got close to him and rubbed itself on his feet, he felt joy for the first time and he didn't care about the saying that black cats brings misfortune and brought the kitten home and named it Blacky. Blacky has been with him since, even when he's kicked out of their house forcefully when he's 18 and just given money enough to live for a year.
(author's note: I know I'm bad at naming lol)
He used the money to buy a very cheap apartment and quit college and tried to get a job, but he never lasts on the jobs he's accepted for because of all the bad luck that happens when he is on the shift. So he compromised and tried livestreaming which worked and lived the life of an otaku. Sometimes when he's free he reads light novels and he loved the concept where the mc is never alone and have friends that never betrayed them, that's why he loved Douluo Dalu and ever since dreamed of having the same bonds.
But no matter how stable Mao Xingyun's life may be, he still felt lonely and he only lives on because of his cat Blacky, so when Blacky died of old age, Mao Xingyun followed her and died at the age of 25.