Raf and Sulfus are the main romantic couple featured within the Angel's Friends series. They meet each other for the first time in Season 1 after Sulfus laughs at Raf's reaction when she believes a truck is about to hit her.
Raf and Sulfus live a difficult love, something that many call a 'forbidden love'. This is due to both being different species that are eternal rivals and some even mortal enemies, she is an angel and he is a devil. Their relationship starts like most relationships between angels and devils: annoyance but soon develops to something else and while Sulfus learns to accept it and enjoys the feelings he has developed for the angel, Raf constantly lives in denial and keeps telling herself and to the devil that their relationship will never work out. This causes the couple to constantly have many ups and downs.
In Season 1 after their meeting, the two constantly bicker at each other, provocking, testing each other's patience and so on...
In another of their rivalry games, Raf and Sulfus chase each other around school in their human forms and are bitten by Reina's spider who should poison and force them to fall in love however the two, by that time, had already developed feelings for each other and the poison only accelerated the process, developing a desire to kiss.
After being caught in, yet, another trap of the neutral, Sulfus protects Raf from being harmed by the Minotaur and ends up badly injured. Suffering over the fact that he could die because of her, Raf almost kisses him but is stopped by both their friends.
The two are then given bodyguards, Gabi and Misha, who are ordered to keep Raf and Sulfus always from each other. The efforts however are in vain for Reina once again interveins and sets another trap that locks the young couple inside a cavern. For the third time, the two almost kiss but are stopped in time by Raf herself who tells Sulfus that their relationship is wrong because he is a devil and she is an angel and to love each other is a sacrilege. Sulfus is hurt by her words but tells her that he will respect her decision.
During the Tournament of Light and Darkness, Reina sends Raf and Sulfus back to the Aztec Civilization. There, they meet Tyco and Sai, who they discover to have been the first angel and devil to have caused a sacrilege by kissing each other.
The two have yet another fight where Sulfus accuses Raf of toying with his feelings all the time, the angel accuses him back by saying that he swore he respected her decision to which he responds that was before he knew she was playing around with him. Sulfus is, however, shocked when Raf tells him that she does love him but words aren't enough for the devil, he wants a proof and demands that she kisses him, the angel refuses again to do so and Sulfus calls her a liar, in responce she slaps him.
A fight heats up between the two which ends with Raf badly injured and unconscious. In despair and not wanting to lose the one he loves, Sulfus awakes a new power: Recover, strangely though it is an angel power.
After healing Raf and telling her that he didn't intend to hurt her, the two eventually kiss for the first time.
Their kiss brings many problems and once back in their time, the two are punished and accused of sacrilege. Their friends and teachers however discover proves that they were manipulated by someone from the outside and the two are acquitted from the accusations however it is hard for both to believe that their feelings for each other were all this time fake.
At Reina's Halloween Party, Raf dresses up as a devil and Sulfus dresses up as an angel however the idea of seeing each other once again as the opposite species hurts both. In a conversation, Sulfus confesses that he had hoped that if for once the two were the same then they could be free to love each other. Later, caught in a sleeping spell, the two dream of their marriage.
After facing Reina and being told that she wasn't born an angel, Raf distances herself from both Sulfus and her friends however, even though he won't admit, the devil keeps watching over her, making sure she doesn't do anything stupid.
Raf asks then for his help to open the door of the Portraits Room so she can see the faces of her, supposely, birth parents but the devil refuses not because he is afraid but because he believes the angel is going crazy with the whole story and it will end up getting her in trouble. Raf eventually convinces the devil into helping her but just as Sulfus predicted it gets them in trouble, the two are tricked and attacked by Reina and Malachia, a fight that the two eventually lose.
By the end of the season, Raf is about to leave Earth and go back to Angie Town but Sulfus calls for her and asks why she was leaving without telling him goodbye. The angel tells him that she was afraid it would be too hard to tell him goodbye, the devil confesses he felt the same way.
This left their relationship in a strange yet close friendship.