Takagi's mask slips just enough to show you why Nishikata keeps falling for her, then she pulls it right back. The OVA doesn't need to go anywhere, it exists to let you sit in the warmth of their dynamic at a water park, watching her win every stupid game while somehow making you believe she's doing it because she wants his attention. It's filler that understands filler's real job: reminding you why you showed up in the first place.

Nishikata and Takagi go along with their classmates Mano and Nakai on a trip to a water park. Before the group can settle on a first ride, Nakai dashes off with Nishikata, and Mano, his girlfriend, is left upset with Takagi. Mano explains that Nakai had promised to ride the water slide with her, a ride said to make pairs who go down together fall in love. Takagi comes up with a plan to bring the couple back together, one that also gives her room to tease Nishikata. The single episode is a comedic romance OVA that came with the ninth volume of the manga.