Ore no Ane ga Konna ni Hinnyuu no Wake ga Nai!?

The protagonist of a mediocre college student had an older sister.
Her sister is a beautiful woman who looks at her, and she has a reputation for being able to work.
At the school where she teaches, she was exactly Madonna’s honorable man.
But that’s just out of place. She was a queen who treated the hero like a guy ○ with a domineering attitude at home.
One day, the protagonist, who was frustrated by her sister, discovers a great secret.
A large amount of putts spilled from her plump chest when she cared for her drunken sister. Her sister had ridiculously small breasts !!!
Her sister, who noticed her, began to confess the secret of her own small breasts, smashing her hero.
No one knows her sister’s small breasts, as she usually manages her tightly.
However, she couldn’t take off her clothes in public because of that, and she had no experience as a man. She says she has never even been dating.
This beautiful sister … she was 29 and she was still a virgin !!
The older sister, who finds her first person to confide in her troubles, asks her hero for help while her domineering attitude.
“How can my boobs get bigger?”

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