I had an extremely estranged sister.
Yuika was cheeky, nosy, and complained every time I saw her. There was nothing cute about her; she was just plain irritating. She had been especially annoying recently and I had been wondering if there was anything I could do about it.

Soon afterwards I found an interesting website.
It was about ‘hypnotism’ and stated that anyone can learn it easily. I decided it was worth trying and immediately gave it a shot, but…

“It’s Onii-chan’s fault that I feel like this…
I’m not letting you go until you cum.”

The hypnotism that I had carelessly attempted brought unexpected results. It brought to surface the sexual urges that were latent within Yuika and she started to sexually advance on me everywhere.

Will the hypnotism wear off, or will I succumb to her sexual advances first?
Just what is going to happen to me…?