The fun part about trying to reverse engineer an electric lighter is that if you accidentally bridge the wrong pins with your multimeter, you can start fires.

someday I'll remember that if you don't write it down, it doesn't count as science.

OKAY SO this is the SUPRUS Electric Lighter.
It's a USB rechargable electric-arc lighter.

you slide the switch, which actually slides the external metal casing, revealing the business end, and turning it on. there's 4 lights on front to show you the charge.

Once it's open, you can push the button, and BZAP.

Inside we've got 5 ICs mounted on a main PCB
The switch is in the middle, and this is pressed by the case when you slide it. That turns it on.

the other side only has the 4 charge LEDs, and a button. this is the trigger.

The battery is 3.7v and 220mAh

There's a second PCB, which is just connected to the USB port on the other side of the battery. This one is USB-C, but with the way they designed it, they could have easily used micro-USB or lightning here.

there's a transformer connected to the contacts.

so here's the annoying thing about this lighter:
it has 5 ICs:
two are blank
one is unsearchable

So up above the main IC, there's a SOT23-5 chip labeled SKAF.
That's a Natlinear XT4052 Standalone Linear Li-Ion Battery Charger with Thermal Regulation.

the "472" (4.7kΩ) smd resistor is setting the charge current: it's set to approximately 200mA here.

And over down past the switch, there's an 8205B.
That's an N-channel power MOSFET, capable of up to 20V and 6 amps.

next to that is Captain Mystery over here, a "63ML" SOIC-6 or SOT23-6 SMD IC.
No results for this on google. My guess is that it's another MOSFET or a DC-DC converter, but who knows.

so an interesting thing is that the microcontroller is always powered.
it would make a lot of sense to have it turned on/off by the switch, but nope. it's always powered. I haven't measured the current, but I hope it has a low-power sleep mode.

And there's this mystery component here. I'm not sure exactly what type of component it is, but it seems to be taking in a voltage at about 4v and turning it into 44v. But the voltage is interesting!

See it's going in like this.
~4V, toggling on/off at 18kHz.
on for 36µs, off for 18µs
So it's on for 64% of the time.