Hatsukoi Killer Kouryaku Keikaku

Sumi, a 5th grader right in the middle of puberty finds crashing at the house of their first crush, Kii nee-chan! They intended to show off their cool, grown-up side, but their plans are completely backfiring...!? Caught up and sometimes rescued by their overpowering big sister. Get ready for an overflow of love and home comedy as it all unfolds.