Nagatoro
Nagatoro is the coolest, most epic girl in the anime 'Don't toy with me, Miss Nagatoro'. She says 'senpai' a lot and will make you regret your life choices.
'Senpai, why did you fail the test? I told you to study!'
'Senpai, why did you eat my lunch? I told you not to!'
'Senpai, why did you not do your homework? I told you to do it!'