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.