If you thought a series about hamsters wouldn't have sad moments... you'd be shocked.
- The episode where Boss found a lost, injured kitten and raised it, but had to give it back to its owner when she was found...
- The ending credits song can cause tears.
- The episode where Penelope crushes on Kylie's little cousin, and is heartbroken when she sees him with Mimi.
- The episode where the Ham-Hams try to build a mini entertainment park to cheer up Mimi, but a storm destroys it. Made worse because of the reason why they're doing it: Mimi is very depressed and scared because her baby sister takes up her parent's time and she fears she's about to become The Unfavorite.
- The episode where Bijou thinks she's moving away.
- In one of the OVAs, Hamtaro goes on a quest to meet his mother. After a long, tough journey, he thinks he has reached his destination... and it's not her. It's a random hamster who happens to look similar to Hamtaro's dead mother.
- The video game Rainbow Rescue has the music for Rainbow Land.