With snow laden on the ground, the Ham-Hams decide to go out and play... but Boss and Stan get into a quarrel over who is the best at snow sports! Who will win the Ham-on-ice Challenge? Boss or Stan?

There is a marathon race at Laura’s school and a friend of Elder Ham’s, the eccentric Auntie Viv, comes to town to participate. When the race begins, Auntie Viv and an equally competitive Boss charge out of the starting gate.

After Laura’s father looses his favorite pair of eyeglasses, he, Laura and Hamtaro go off to the optical shop for some new ones. After trying on several pairs, a frustrated Mr. Haruna decides to keep looking for his old one’s.

Hamtaro and the family dog Brandy go with Laura to a dog-sled race. Brandy, who only gets exercise from yawning and walking in and out of his doghouse, just goes to watch; but he begins to worry about embarrassing Laura with his laziness, so he decides to sign up for the race.

Boss, the self-appointed chief of the Ham-Ham Clubhouse is acting strange lately, and the other Ham-Hams are concerned. They decide to follow him one day and soon discover that he’s caring for an abandoned kitten.

It is Valentine’s Day, and Laura decides to make chocolates for Travis. In the Ham-Ham Clubhouse, the traveling Auntie Viv appears, wanting to give a Valentine gift to Elder Ham. The girl hamsters are thrilled at her romantic gesture and encourage the boy hamsters to help Auntie Viv find Elder Ham.

At the Ham-Ham Clubhouse,the Ham Hams see a rainbow. Some of them think they can nibble on it. Bijou arrives after the rainbow disappears and she and the Ham Hams think she will "lose her colors" now. Boss tries to find a rainbow for her but is unable to.

Pashmina is going out for the day without Penelope, so in an attempt to impress Pashmina, Dexter and Howdy volunteer to baby-sit so Penelope won’t be alone. Howdy and Dexter, both competing to be the best babysitter end up fighting with each other and a neglected Penelope wanders away.

It’s almost Mimi's birthday and the girls celebrate with Chinese Doll displays and treats. As the Hamsters are trying to understand the holiday, they find themselves following Mimi down the street, because they see her carrying the food they love, Rice Crackers.

When Maria's parents decide to go back to France so she can study piano, Bijou must bid her Ham-Ham friends goodbye. She finds it hard to tell them and when she finally does, the hamsters are in shock.

Kana’s cousin, Dylan lives on a farm called the Flower Ranch with his parents and pet hamster, Pepper. One day Kana and Laura and their families visit them and bring Hamtaro and Oxnard along. On the way, Oxnard tells Hamtaro about the huge crush he has on Pepper and hearing this, his good friend Hamtaro encourages him to tell her about his feelings that day.

When Mr. Haruna plans to go on a business trip to their old town, Laura wants to go along, hoping to hook-up with her old friend Melanie. After Laura fails to reach Melanie by phone, she decides to send a letter. But Laura never gets a reply so a curious Hamtaro takes it up at the Clubhouse and says he wants to investigate. Just then Jingle appears and Boss and the seasoned globetrotter agree to solve the mystery.

Hamtaro wants to learn to fly after Jingle relays the “Tale of the Flying Hamster.” Then they find a scroll about this special hamster in Panda’s house and his determination increases. In the meantime, Laura is trying to decide on a flower design for a school project and goes to the park, allowing Hamtaro time to persuade his Ham-Ham pals to join his new adventure.

Hamtaro, hearing Laura and Kana talking about going on a picnic, thinks that it would be a great idea for the ham-hams as well. He takes the idea to the ham-ham gang. Everyone thinks it's great, except for Penelope and Bijou, who don't know what a picnic is and wonder what involves.

Laura visits the local museum to gain some information for an independent study assignment. As she talks with her family about it, they talk about something at the museum that they think looks like a giant sunflower seed. Hamtaro, listening in, focuses on ""giant sunflower seed."" He takes the news to the ham-ham gang, who wonder about the origin of this giant sunflower seed. They think maybe that aliens brought it to the planet Earth. One thing they do know: they have to get the museum to check this out.

Kana's country cousin, Dylan is coming for a visit and he's bringing his hamster, Penelope, with him. Oxnard is still madly in love with Pepper and can't wait for her to come. Meanwhile, all of the ham-hams are planning a surprise party to welcome Pepper.

When Laura and the other students study zoology in Mr. Yoshi’s class, everyone brings their pets. While the animals play on the counters and in the strange science sinks, Oxnard strays off to look for food. He finds some corn and starts eating it, but then realizes he’s in the cage of the mean Chicken Trio: Gonzales, Vinny and Capone.

On Children’s Day, Laura’s Grandpa comes to visit, bringing with him his latest invention, a fully automated treadwheel. He decides to test it on Hamtaro and before long, the wheel throws Hamtaro across the room. Laura gets upset with her grandfather and leaves the house.

Laura and Kana visit the Aquarium with their fathers, and the Ham-Hams follow along. Inside the Aquarium, strange sea creatures overwhelm the hamsters, but Hamtaro recognizes it as the place from the fairy tale that Laura read the night before.

There is a Sports Festival at Laura and Kana’s school, and the girls are participating in the Parent-Child Triathlon with their fathers. The Ham-Ham’s decide that they want to organize a competition of their own, so they attend the festival to see what’s involved.

Mr. Yoshi, Laura’s teacher, cannot forget Charlotte, the beautiful woman he met in the wild classroom chicken incident, so the Ham-Ham girls (who are natural romantics) set out to find her.

During the rainy season, the Ham-Ham’s want a change of atmosphere so they decide to redecorate the Clubhouse. After they finish, they try to go outside, but find that the door won’t budge, because a mole dug a hole while they were decorating. The mole-hole has brought mud & water into their tunnel, and it threatens to seep into the Clubhouse!

After Laura's parents have an argument, Dad leaves the house with Laura. As a worried Hamtaro watches them go, the Ham-poet Jingle appears. In the meantime, Laura and her dad go to the department store and buy her mom a pretty pendant for Laura’s parent’s anniversary, but when they get home, Laura discovers the pendant is missing.

Laura’s social studies class takes a field trip to the harbor to ride a sightseeing boat. Boss claims to be an expert on boats and harbors, so the hamsters follow along. When they get there, however, they soon realize that Boss has never been near a boat or a harbor in his whole hamster life.

The hamster siblings, Stan and Sandy have one of their heated arguments, and Sandy’s ribbon is torn and Stan’s maracas are broken. The Ham-Hams decide that the twins need to make up, so they plan a surprise party for their birthday.