#ofc in a way that L is directly working with the government and other worldwide police forces

[astersofthesky]

Maybe the reason why yotsuba Light and pre-kira Light is so vastly different in personality (he's more 'genuine' that is) is because yotsuba Light had L that kept him from feeling that mind-numbing boredom that pre-kira Light experienced prior to getting the death note.

Pre-kira Light literally had nothing to keep him entertained and that he was too powerless to change the broken justice system, so he's more closed-off and serious, literally just living through the motions like a dead man.

On the other hand, yotsuba Light met someone who's not just on par with his intelligence, but also one insufferable enough to annoy him that never made any dull moment possible with L around. Aside from that, yotsuba Light is literally working alongside the world's greatest detective helping him solve the world's hardest case that involved the justice system, so yeah, yotsuba Light really will take L's side of "justice" because detective L is legal whereas Kira's actions are not.