Ai O Ataeru Kemono-Tachi (www-readlightnovel-me)

40-year-old virgin, Japanese old man, found himself waking up in a different world. When he wakes up, he found out his body become young again. With no help from anyone he spends several years becoming a s*ave and spend his days full of hardship. His life in the living hell is continued, until he meets him… This is a…