Call to undefined method Illuminate\Database\Query\Builder::user()

Why my one to one relation method doesnt work ?

here my controller

use App\User;

public function delete ($id){

$student = \App\Student::find($id);
$student->user()->delete();

return redirect('/student')->with('sukses');

}`

Here my user model

public function user(){

    return $this->hasOne(Student::class);
}

Student model

public function Student(){
    return $this->belongsTo(User::class);
}

via Chebli Mohamed