Three Years of Family Life Where My Little Sister Takes My Semen

It was out of my expectation, I didn't notice that my little sister is this amorous...
Let's educate her about things from general mischief to creampie H!

[Perverted Mischief]
1. Fapping with little sister's toothbrush
2. Check smell right after she uses the restroom
3. Check her lingerie
4. Fapping with her lingerie / school uniform
5. Inject semen in her yogurt

[Observation Diary]
This is one of my daily routines to take a note
about little sister's growth every midnight.

I sneak into her room and take a photo of her crotch...

[Education Plan]
As I get close to little sister, she comes to talk about
her worries about physical development, for example.

"Is my breast growing bigger...?"

H worries are the sign of perverted physical intimacy!!

[Your "Oniichan-ness" Is Tested]
At the beginning of the game how you are suited to being oniichan is tested.
The result affects the game progression.