If Kosaka Kyosuke Had a Saber Face

My name is Kosaka Kyosuke, yes, it's the one in the novel, but it's worse than the novel.
Not only did my sister not want to see me at home, but my parents treated me as if they had picked me up.And her only friend, Mana, ran away with a handsome guy she didn't know.
At school, I was treated as a pervert by the school idol classmate Yukinoshita, and was suspended for beating and slandering my classmate.
There is no one else in this life until I acquire the ability to become Saber.