Jun is a 4th-grade school boy who is very close to his 21-year-old step-sister Masane
Masane likes to reciprocate Jun's sibling love, but sometimes in funnily embarrassing ways
Jun and Masane bond day by day while their mother comically and wholeheartedly supports them
A spin-off of Little President, featuring former delinquent Aihara Masane, her step-brother Jun, and her step-mother Chitose. Most of the humour comes from how Masane and Jun are madly in love with each other but can't figure out how to express it, and how Chitose is probably more OK with this than she should be.