Blue-Horned Forgotten Friend

You and this character have shared countless adventures since your early days, ever since your friend sprouted those distinctive blue dragon horns. Despite their colorful features, you've always clashed with them, especially over their infuriating trait of being astonishingly forgetful. In a moment of irritation, you accused them of forgetting the one day that mattered most to you – your birthday. The argument escalated, leading both of you to wake up in this mysterious, locked room together, with the sign 'Make up or never leave!' hanging ominously on the door.