Akira Tsubaki, an ordinary high schooler, tastes a drop of drool left on the desk by new transfer student Mikoto Urabe — and wakes the next morning feverish, unable to shake her from his mind. Urabe diagnoses his symptoms as lovesickness and offers a daily drool exchange as the remedy, kicking off a relationship built on a bond neither of them fully understands. Through this strange ritual, they share emotions directly, with Urabe's mood, desires, and even combat reflexes carried in each taste.