My father remarried. My new mother, Ai-san, was my elementary school teacher. Ai-san has always treated me like a child, and is unusually affectionate. I think it's a bit too much, but... when I'm wrapped in those big breasts, I don't care about anything else. I was also frustrated when I started studying for entrance exams, as my grades didn't improve. Then Ai-san offered to be my tutor, and said, "I'll give you a reward every time you get the answer right," and the rewards became more and more extreme with each correct answer...