Tomoya Mizuhara's home life is rearranged when his father remarries and seventeen-year-old Ichika moves in as his new older stepsister. Ichika promptly falls head over heels for him and smothers him with affection, and each short episode follows her relentless, over-the-top attempts to dote on a flustered Tomoya at home, with her friends Ruri and Marina piling on. Episodes run roughly three minutes.