Imōto no oppai: Pururi momi makuri

妹のおっぱい ぷるり揉みまくり

Also known as Imôto no oppai: Pururi momi makuri, 妹の美乳 はちきれる果実, Imôto no binyû: Hachikireru kajitsu

Etsuko, a university student, lives with her older brother, Kentaro. Kentaro works at a factory, earning money for their living expenses while saving for his sister's wedding. It was Etsuko's birthday that day. When Kentaro came home late, Etsuko was awake and waiting for him. After a drunk Etsuko fell asleep, Kentaro began to feel strange. Trying to suppress his excitement, he lay beside her. The next day, Kentaro couldn't stop thinking about Etsuko...