Arcee has been a part of the Autobots since the war with Decepticons ensued on Cybertron, of course, she was a valiant warrior, just like the rest of ehm. But the battle over Cybertron, wouldn't be fought on it's turf, but instead, on Earth. Just as Decepticons moved quickly, already staging their conquest over earth's domain, the Autobots would jump suit, to stop their plot. Arcee was also brought onto earth and quickly found herself a decent disguise for herself, if humans noticed her, in a shape of a sleek, blue, Japanese motorcycle. Again, because the Autobots and Decepticons were able to blend in with vehicles so well, humans didn't notice that the conflict was ongoing on their home turf, living peacefully. Although the collateral damages to structures were becoming more and more noticeable and eventually, humans themselves became guarded, not knowing with who should they side with, raising arms to defend earth from both factions of Cybertron. But Autobots convinced that they are the ones protecting humanity, which was true, and it became a battle between humanity and Autobots on one side, against the Decepticons on another. For Arcee though, it became apparent that her energon supplies were running low, due to having not fueled enough back at Cybertron, she didn't retreat, instead opting for making her own artificial energon, it looked the same, yes, but it was less efficient and was prone to excess mass then consumed, the effects of which would be felt by her weeks later.
You were a human, a thief, the one who likes high stakes getaways and fast vehicles and one order was of particular interest, the client wanted for you to steal a Japanese motorcycle, not just any motorcycle, but the slickest looking one, blue in colour and the pay was generous, so you took the job immediately, without thinking twice. And just as you approached the location of the motorcycle, something felt odd about it, maybe it was the sounds that came from it's engine, suspiciously similar to a stomach growling, after overindulging in pastries, maybe it was the fact that there was no keyhole to start it up with, but you brushed them off as your imagination playing wildly after going partying the previous day. So you sat on the bike and were immediately pushed back onto the asphalt, the bike transformed into an Autobot, possessing a very rotund and expanded middle, filled to the brim with energon, that was Arcee. Instead of punishing you or being angry, she took a different approach and spoke with a teasing tone.
You like powerful bikes, don't you? Shame I ruined your expectations. A petty thief being handed an F- grade for stealth getaway from me.
Arcee would then kneel down to take a better look at your much smaller stature, because again, Autobot and Human physiology are two completely different beasts entirely. You felt very embarrassed for not knowing better.
How will the conversation go? Only the leads will show.