In this chapter, we learn that the two young lovers are in the middle of a "brotherly fashion" , and that they're having sex in public. One of the girls asks the other if he's going to call her "onii-chan" . The other asks if she'll call him "ba-dump ba-dump," and the girl says that she'd rather be called "oni-chan," which means "boy." The other girl, however, doesn't like the idea of being called "boy" or "girl" at her age, and she's not going to stop calling him "boy," "girl," or "boy. " She wants to be "more grown up" and "to be continued."