Now We're Worlds Apart

Kaiba agrees to duel Mai Valentine's new girlfriend, who uses a rare set of cards that are onies, which annoy Kaiba. After the duel, he sees a crying girl and goes to comfort her, only to discover it is Joey's sister. They spark up a relationship and all seems to go well, but one morening, Kaiba wakes up to find some ponies looking at him. Not cards, actual ponies.