On Good Terms with: The Runaway Debtors Grim Matchstick , Hilda Berg This is the tale of two brothers, Cuphead and Mugman from the Inkwell Isle, who one day wandered into the wrong side of town and ended up entering into the Devil's casino.
They soon found themself on a winning streak playing craps until the Devil himself showed up and challenged them to a High-Stakes bet: If they win, they get all the riches but if they lose, the Devil would take their souls. Thanks to Cuphead's greed the boys ended up losing and the devil forced them into collecting the runaway soul debtors just to spare their own souls, although they both later rectified the mistake by defeating the Devil and burning all the soul contracts, making them both heroes for the people of Inkwell Isle.
Their ascension wasn't an official one, as both boys wandered into the pantheon without anyone noticing and only after they were caught sneaking around the Treasure Vault were the boys allowed to ascend for real. Their tale has taught many about gambling and how it can mess up your life. And how you don't make deals with the devil. Given their own experience, both siblings refuse to get near the House of Demons in fear that the Devil would be present wanting revenge for what they did to him.
There were many different incarnations of Satan in there but none were the Devil from Inkwell Isle so they felt relieved for that but later they learned that a sizable chunk of those demons are planning something for the Cup Bros, which has unnerved them.
While they are not demons, the Incubators have been another group that the cup brothers dislike heavily. They feel pity for those who were tricked into making a contract with them. Made good friends with different deities from the 's era of cartoon animation, most notably the likes of Mickey Mouse and Oswald the Lucky Rabbit, whom the Cup Brothers have taken direct inspiration from.
Both brothers also left a good impression on the video game deities too. Most notably they ended up befriending Mario and Luigi, who share a lot of similarities with them.
At least the little cups don't have to go around saving princesses. Mugman has made a huge effort in keeping his brother away from the House of Luck and Fortune given that his gambling problem is what caused the whole ordeal with the Devil in the first place. Both brothers were also startled when they came across the D'arby Brothers considering what they do , especially Daniel who resembles King Dice a lot.
When they heard of Pleasure Island and how many happy boys have a fun time there, the Cup Bros felt like they were being deceived. Turns out that the Coachman had heard of their ventures and wanted to punish the two naughty little cups on behalf of King Dice who had told him about them.
What scared the boys the most was how similar the coachman's freaky smile was to King Dice's but they managed to get away from the Coachman after giving him a karmic beating. The boys were quick to befriend Peacock, who also acts and behaves like she was a cartoon from the 30's.
Their personalities aren't that far off either, as Peacock and Cuphead share the same personality with being rash and hot-blooded, which makes Mugman feel like he has to be the Straight Man whenever these two hang around.
Peacock feels she can relate to what happened to the boys, although the whole soul collecting business reminds her a bit of the Medici and what they did to her, but she nonetheless is glad that they beat up that lousy Devil in the end.
Of all the deities they have met, they never thought that the one who would relate the most to their story is none other than Johnny Blaze. After all, he was forced to work for Mephisto before he bailed out and went to do his own thing, so Johnny respects the boys for that. Mephisto on the other hand has a very low opinion on the Cup Brothers.
Rumors have been circulating that Mugman may have a secret crush on Cala Maria. He has denied all claims, but his brother likes to tease him about that.
One trip around the House of Gaming let them befriend the Human Child, whose adventure was somewhat similar to theirs. His pacifistic ways reminded them about a turtle who taught them that violence could be avoided if they tried, and so the brothers have tried a more pacifistic approach to certain scenarios Plus they haven't really killed anyone, although they usually avoid talking about what happened with Goopy Le Grande and Wally Warbles.
Many have wondered how they would feel if someone drank from their heads. They don't necessarily mind if you ask nicely, though many find it strange that Mugman will drink from himself before the start of a fight. Given how many different foes they have faced in their adventures, both Cuphead and Mugman have been weary to meet a few deities who either resemble them or are a direct reference to them , even if the little cups are on better terms with the runaway debtors ever since they burned all the soul contracts.
One day visiting the house of Nature they stumbled upon Flowey, who like always, tried to play a trick on them. Unbeknownst to Flowey, the brothers' encounter with Cagney Carnation has taught them that not all innocent-looking flowers are harmless and they were very good at avoiding his "Friendliness Pellets".
Flowey promised to get back at them in the future. After all, their dodging skills proved quite impressive and he'd like to test them again. Jafar was seemingly interested in the powers the two cup boys possessed and tried to ambush them in an attempt to get a better look at them and see if he could steal and harness the brothers' powers for himself.
However, the brothers were very familiar with all his tricks after their encounter with Djimmi the Great and beat the ever-loving crap out of Jafar, leaving the battered wizard to crawl away, swearing revenge. While they aren't necessarily hostile, the cup brothers have their doubts about the Blue Slimes.
For all they know they could be related to Goopy Le Grande and may want revenge considered what happened with him. When they first saw the Iron Giant, the brothers thought their old enemy Doctor Kahl had invaded the Pantheon with a larger robot, seeking revenge.
Eventually, however, they learned of his true nature, and while still a bit wary of him, they agree he is definitely a nice guy and also because they fight via Finger Gun , while the Iron Giant despises guns A similar event to the giant happened with Princess Bubblegum, with the cups thinking Baroness von Bon Bon had ascended.
After they were proven wrong, Bubblegum was quite willing to spend some time with the pair, and hopes that they can get along with fellow adventuring brothers Finn and Jake, should they meet.
Speaking of soul contracts, they always take potshots at Kyubey if they ever so much as see his face; his kind of contracts, even though he holds up their bargain no questions asked, the fact he targets innocent young girls who would not be likely to capitalize on these deals not to mention inevitably becoming Witches means he's arguably worse than the Devil they used to work for.