Moominpappa's adventure companion from his youth. He loves inventing and tinkering with machinery, and is skilled at creating various tools. Bright and proactive, he is the type to try out ideas as soon as they come to him. Though he can be a bit clumsy, he is a reliable friend who cares deeply for his comrades. He travels alongside Moominpappa and the others while enjoying the adventure.

Moominpappa's adventure companion from his youth. He has a somewhat timid and anxious personality, but he is kind and cares for his friends. With a calm demeanor, he is the type to observe his surroundings carefully before acting. Though reserved during their adventures, he is a steadfast presence who supports his companions.

Moominpappa's adventure companion from his youth. He is lazy and tends to lounge around, yet he has a somehow lovable personality. He loves eating and taking it easy, and is often found lying down. While he doesn't take much initiative, he stays with the group. He possesses a laid-back, easygoing atmosphere and wears an old red hat.

An adventure-loving young man who traveled in search of freedom. Highly inquisitive, he is the type to dive headfirst into new things and unknown worlds. He has a leader-like quality and cares for his friends, having shared various adventures with Hodgkins and The Muddler. A bit of a romanticist, he cherishes his own story.