"We can't be together anymore."

During high school, Hachi met Kuma, a strong-built guy, and Hanabi, Kuma's childhood friend. They become an inseparable trio. However, Kuma confesses to Hachi and Hanabi slowly stops showing his face when they officially start dating.

Later, when Hachi asked Hanabi why, he replied, "If I'm near Hachi, I'll stay as a hedgehog forever because of my guilty conscience." Discovering this truth, Hachi disappears from both their lives. Yet, these three met once again… but even though there are three, there is only a place for one lover.