Ninja trainee Shinobu goes on a mission for her perverted headmaster to collect underwear from high school girls, first targeting Kaede Shiranui.

Rainy weather sends the bored ninjas to search for the Loch Ness Monster in their pond; ninja-master Onsokumaru and a masked Sasuke keep a close eye on a girl-girl dating spectacle.

Onsokumaru gets angry at Shinobu's little sister, Miyabi and decides it's time for a little one-on-one; Shinobu is kicked out of the manor, and heads to Kaede's family.

Rising temperatures give Onsokumaru a perfect opportunity to get Shinobu and Kaede into their swimsuits; Miyabi has a crush and uses the Ninja Pharmaceutical Group's special love potion to help things along.

Onsokumaru is sent to Hell and encounters demon schoolgirls, demon wives, and demon in-laws; when it's too hot to train, the ninjas plan a Summer Festival to brighten the mood.

With Shinobu stuck at Kaede's house as a typhoon looms, those left at the ninja manor witness Onsokumaru's darkest hour; when Onsokumaru offers his wisdom to a mushroom picking expedition, the ninjas are in for a magical ride.

Onsokumaru becomes melded to his arch-nemesis Miyabi and the gang try to help detach him; when the men want to play baseball, the girls are told to take their games someplace else.

Kaede's school holds a festival, complete with a haunted house; Shinobu gets a new pet, a cute and cuddly five metre tall monster plant.

At a hot spring, Onsokumaru tries to see some skin, but Miyabi's guardians stand in the way; when Kaede gets sick, Shinobu and Onsokumaru take care of her.

The ninjas celebrate their first Christmas and Kaede teaches them about the holiday spirit; a bit of year-end cleaning yields a box filled with misfortune, subjecting Kaede, Shinobu, and the rest of the ninjas to one bizarre curse after another.

Sasuke has an adventure filled with full-throttle action; the ninjas put on a play of the Grateful Crane story, but have trouble remembering how it goes.

Onsokumaru's secret comes to light, and the shocking truth threatens to change everything for Shinobu; with her goal of becoming a full-fledged ninja in sight, Shinobu just has to pass the dreaded Ninja Graduation Exam.