Natsuhiko, the heir of a rich family goes to spend a studious summer at the bungalow his family owns. He meets Ryo, a childhood friend but Ryo seems to have forgotten him...

Nii-chan is about a story between a young boy in grade school who often goes to this 'Nii-chan''s place to play video games after school, however the 'Nii-chan' has ulterior motives and asks for sexual favours....