Ame is restrained by the Mad Dentist and is about to undergo dangerous cavity treatment. It's a desperate crisis! But is there a secret in Ame's mouth...?

Caries, a cavity, remodels Ame's teeth without asking and pushes her around. Seeing that Ame can't fit in with her friends, Caries tries to solve it with her specialty: DIY.

Ame is happy that her baby tooth fell out. But that was Caries' precious TV! Caries carefully nurtures the newly growing tooth, eventually growing it into a giant TV, but...

Ame is banned from eating sweets by her mom. Unable to watch Caries suffer from not eating sweets, her friend Mikan secretly gives them sugar, but they get involved in unexpected trouble.

When Ame wakes up, Caries and a mysterious fish, Harold, are flirting inside her mouth! Ame doesn't accept Harold, who claims to be Caries' boyfriend. However, Caries is head over heels for Harold...

Believing the rumor of the Tooth Fairy who "exchanges lost teeth for money," Ame and friends sleep with teeth under their pillows. But they were all stolen! Caries stands up for the sake of the children.

Mom took Ame to... the dentist!? If the cavity is found, it's game over! Ame and Caries panic and frantically clean up Caries' room, but...

Ame finds a toy she wants and tries throwing a tantrum imitating Mikan and the others, but she isn't making enough noise to get it bought. Unable to watch, Caries helps her out, but...

The real Tooth Fairy got caught in the trap set to catch the tooth thief!? They immediately try to exchange the lost tooth for money, but the Tooth Fairy's assessment is stricter than imagined.

Caries fights with Ame and storms out of the room. She relies on Mikan and the others, trying to get them to let her stay in their mouths, but...

A massive amount of teeth growing inside Caries' room! It seems Ame entered a cursed place. To increase the teeth, Caries tries various curses on Ame.

Ame and Caries write letters for what they want for Christmas. However, the presents don't arrive, and Caries gets depressed. Just then, a certain surprise arrives.