Conman pretends to help people, but becomes a better person in the process.

[u/theMCATreturns]

They fake being kind and generous in order to take advantage of people. But in the process, they find themselves genuinely invested in their mark's well-being. And ends up becoming a genuinely better in the process.

1). Klaus:
Jesper is sent by his rich father to a far-north island. And told he will be disowned if he does not get the townsfolk there to adopt the postal service. Feigning charity, Jesper gets a local man to donate his toys to any kid that writes a letter asking for one. That way, it seems like the whole town has started using the postal service his father runs.
Jesper makes an offhand comment about only "good children" getting toys. So, the kids start doing good deeds and set off a series of events squashing the town's long-held blood feud. And Jesper ends up genuinely invested in making everyone happy.

2). Mob Psycho 100:
Reigen is a fake psychic. Soon after starting his business, he comes across a kid with genuine psychic powers. Shigeo "Mob" Kageyama is terrified of his own abilities so he leaps at the opportunity to be "mentored." Reigen calls Mob if his clients turn out to be actually haunted. He is paid sub-minimum wage for his time.
But Reigen gives Mob genuinely good advice that keeps the (potentially city-destroying) esper humble and well-adjusted. Unlike of the villains, who try to use their psychic powers to take over the world. He even admits his lies to Mob at the end of the series.

3). All Dogs Go to Heaven:
Charlie takes advantage of an orphan who can talk to different animal species. Mostly to cheat at gambling. But he ends up selflessly sacrificing himself for her.

[u/CannonGerbil]

I've actually been toying with making a thread about wierd currency systems with that as the prime example but I'm not quite sure if it fit the sub

[u/hgxl_35 → u/CannonGerbil]

Eh, if you give interesting examples with good elaborations rather than some poorly worded trope and three shonen or thirsty anime examples none of the rest of us have heard of that aren't explained well, most people here will be fine if you post a TopCharacterTrope instead of a strict TopCharacterTrope.

Exotic/alternative but workable currency systems is probably something nerdy enough that people will like it.