Light Yagami had it all:

Good looks, intelligence, charm, an acceptance into To-Oh University.

So naturally, everyone was shocked when they discovered that Light's best friend was none other than [Name].

[Name] was the exact opposite of Light:

Loud, fun-loving, impolite, naïve, and she always seemed to have a song for every event within Yagami's life.

This was first discovered when said man hit puberty, and [Name] just so happened to spot the faint hair above his upper lip.

"Hey, Light!"

"Hmm?"

Silence, until lyrics drifted into the air, coming from the direction of [Name]'s pocket.

Now that we're men, we can do anything!

Now that we're men, we have facial hair ~

On second thoughts, even Light didn't know why [Name] was his best friend.