"If you don't want them to find out that you're a girl, then be my dog."
Thus began Tachibana's humiliating life as Haruki's servant. But Haruki's treatment of her is nothing but petty harassment...Then who shows up in that same immature person's life but his twin brother, Haruka? In the face of Haruka's bizarre love for his brother, Haruki's behavior does a complete one-eighty...! Will Tachibana cut into what they have between them!?