A work depicting four hidden truths (sexual encounters) of younger sister Hinano. To her big brother, she argues with righteous indignation: "Spying is gross. Don't siblings deserve privacy?" To her friends, she speaks seductively: "Whenever my brother sees my breasts, he instantly gets hard. But they're warm and delicious, you know." To her boyfriend, she expresses pure romantic longing: "I'll indulge your whims. I won't make a face even if you cum all over my face. But I can only be with you sexually." Finally, she abruptly shifts her attitude: "The dorm manager, the image club customer, and you, big brother—you're all disgusting." The appeal lies in her contrasting behaviors toward different people, revealing the complexity of human relationships and the true feelings of sister Hinano.