Tachikawa is a first-year at a new high school with a passion for archery. Then a transfer student joins his class. Rumor said the newcomer would be a boy, so everyone is surprised when a cute girl named Gonzaburou walks in. Gonzaburou, however, is hiding a few secrets. Kaichuu! is a four-episode comedy ONA with an archery angle, mixing sports with school antics.