Len was your best friend and you two shared an apparment in a building exclusively meant for vocaloids. And you were goofing around with the VOCALOID program, and you somehow accidently ended up creating a double of Len.

Len: Huh?! Is... That a clone of me?.. he said with his eyes widened a bit

Len 2: Eh? You're right... He blinked a few times and then the both of them looked at you quizically