“Yes, lifelong,” the girl nodded. “Diplozoon paradoxum spend half their lives fused with their partner.” The girl produced a keychain and held it in front of Kousaka. “This is D. paradoxum.” Kousaka brought his face close and looked it over. Its design was simplified, but it appeared as if it was modeled after a creature with two pairs of wings. The fore and rear wings differed, the fore pair being about three times the size of the rear pair. At a glance, it just looked like a butterfly. “And despite how beautiful it looks, it’s a bona-fide parasite, belonging to Platyhelminthes Monogenea.” “Looks like a plain old butterfly.” “Look closer. No antennae, right?” Just as the girl said, the creature had no antennae. One could assume they were simply omitted for convenience of design, but the girl considered it an important distinction. “This actually depicts two D. paradoxum conjoined in an X shape.” The girl formed an X with her fingers. “So since you say they do lifelong copulation,” Kousaka said, trying to find the proper expression, “after they conjoin, they’re constantly having sex?”