[Zaki Zaraki] Shougakugakusei Ch.1

After her mother leaves following an affair, a young schoolgirl fills the lonely void in her father's life—becoming his willing replacement in every sense. When he takes her to visit an old friend who shares his particular interests, she's led into an underground room where another girl named Hikari awaits, collared and eager. What begins as a father's comfort soon spirals into a shared arrangement between two like-minded men, with both daughters discovering pleasure in serving them—and each other. The fathers watch their girls entangle with guilty satisfaction, admitting they're completely hooked on this arrangement where everyone's doing it.