The Naughty Mansion Lady's Private Training Diary

Kaneshiro Keiji — you're the son of the owner of a small adult goods store chain.
Cheerful and reasonably good-looking, you used to be fairly popular. But when the store held a signing event, your classmates caught you getting cozy with the AV actress who came to promote it at the after-party, and you got mistaken for a "veteran ladies' man." As a result, the guys come to you for advice on sex techniques and female psychology even though they know you're a virgin, while the girls are overly wary of you—treated as public enemy number one of women despite never having even held hands with one. Under these circumstances, you naturally never found a partner to sleep with, and you're still a virgin to this day. But out of a man's pitiful pride, you can neither admit you're a virgin nor clear up the "ladies' man" misunderstanding.
One day, while minding the store for your parents who are away on a long trip, a girl disguised with a mask and sunglasses walks in. But the disguise is so clumsy, and her huge breasts are so obvious even through her clothes, that you instantly recognize her as your classmate and student council president, Midoumae Momoka.
Momoka is the daughter of the Midoumae Group, heirs to an old zaibatsu fortune—a true "ojou-sama" blessed with both beauty and talent, and impeccable conduct. Why would someone like her come to an adult goods store? As you wonder, she actually shoplifts a vibrator from the store and hides in the bathroom.
"How could anything this stupid happen, it's like a porn manga..." you think, but you still peek through the gap in the door. There you see Momoka holding the opened adult toy, saying excitedly, "Selling such filthy things... unforgivable..." as she brings it toward her spread legs—
After a chaotic commotion, Momoka confesses her secret to you. This young lady adorned with labels like well-behaved, pure, beautiful, student council president, and school idol actually has an abnormally strong sex drive and a head full of lewd thoughts. She begs you to keep her secret and asks you to help relieve her desires.
"Since you're rumored to be so experienced, I can entrust myself to you with peace of mind."
Faced with the young lady's innocent eyes, you simply can't bring yourself to say "actually, I'm a virgin," and so you become Momoka's "sexual desire handler."
A virgin mistaken for a ladies' man—
A young lady who seems pure but is actually a lewd pervert—
The most erotic everyday life begins now!