Onee-chan ga Kita

The story revolves around Tomoya Mizuhara,

a 13-year-old boy who suddenly gains a big sister when his father remarries.

17-year-old Ichika is a little strange,

and her affection for Tomoya is rather overwhelming,

if not scary. On top of things, Ichika’s friend Ruri is the ultimate sadist.

Then there is Ichika’s big-breasted quarter-Japanese friend Marina.