S-So This is How it Goes, Huh...A pretty girl named Rina Saijō transfers from the prestigious all-girls Shirogane Academy to Haruka and Akiho's mixed-gender school in search of a romance with a man. Befriending Haruka and Akiho, she eagerly begins to collect any information about how to form a male-female relationship from them, and in order to deepen her information, she takes the two to the zoo, where - again to Haruka's shock - he finds himself confronted with all sorts of ambiguous allusions whilst observing the wildlife. Following the visit, Haruka and Akiho encounter Akiho's parents, who have also visited the zoo on their own, and the four incidentally conclude the day taking a rest at a love hotel.