If Only

'If only I had realised it sooner.' 'If only I used my head for once.' 'If only I had paid more attention to her.' 'If only she had told me something.' 'If only I had been there that day.' 'If only...' A/N: I do not own Haikyuu. All rights go to the creator of haikyuu. This is an x fem reader! I'll make sure to make...