Senpai is someone who will never notice You. This is because Senpai is better than You in every way, but You still love Senpai for some reason. You seem to be in love with Senpai, but he will never notice you so your life will suck ass forever. Since Senpai is a male, You might be gay for Senpai if you are a boy. If Senpai is a female a.k.a Senpai-chan, you might be lesbian for Senpai-chan if you are a girl. However, in Soviet Russia, you notice Senpai. 私に注意してください、先輩。