Iyashinbo ~Sekai de Ichiban Suki na Hito~

Makoto is often a senior high school student. He lives regarding his mother, Tamami, because his father passed away as he would be a kid. Some day, his dick gets erected usually whilst awakens, but never gets small. Tamami finds it, and immediately takes him to hospital. According to the doctor, he has a continuing erection disease, and is required to ejaculate periodically. Since then, she gives him a blowjob everytime necessary. However, she gradually gets sexually excited....