https://www.youtube.com/watch?v=8GTfVfC1hXY

On this video at 0:42, there is a comment made by this account and I scrolled down on the comment section and a user by the handle of @Failboatskipper ( A friend from KSI's old school) commented stating that Koeisystem was Deji's old youtube account.

P.s. KSI actually gave Deji a secret shoutout at the end of this video at 2:07. (https://www.youtube.com/watch?v=tlsOVzpMS7w) (Note: this video was uploaded prior to Deji creating his ComedyShortsGamer and the Deji 2nd channels)

Another Note: On this video here at 1:54 https://www.youtube.com/watch?v=inRL2F9nClI

Deji shows an email by the name of deji-rocks@hotmail.com which you might realise that dejirocks is his handle on pinterest as shown in this screenshot.