Jerome Kellerhals, born in Switzerland, has been around bonsai for as long as he can remember. His mom lived in Japan and was a big influence in his love for the art. However, it wasn't until he moved to the United States that he started studying it in depth. Suthin Sukosolvisi, Min Hsuan Lo, and Nacho Marin have influenced his work.

He is known for being a creative “rule breaker.” He created a unique piece using the technique “root over rock” but using a statue instead of a traditional rock. He called this tree Angkor, in honor of Angkor Wat, which he first visited as he traveled around China and Cambodia. This tree has been exhibited in many bonsai conventions in the USA and was selected for the display of the 2019 Epcot Flower and Garden Festival in Orlando, Florida.

Over the years, Jerome has given bonsai demos for various corporate teams, bonsai clubs, and garden clubs. He also has taught beginner classes at his retail store for over 1,000 bonsai enthusiasts. Jerome has written multiple articles on tropical species of bonsai for the very popular Bonsai Focus magazine, recognized worldwide.

Mariannjely (Mari) Marval has an MBA in marketing. Mari and her husband, bonsai pro Jerome Kellerhals, own The Bonsai Supply, a bonsai retail location offering trees, supplies, and classes. Mari and Jerome can also be found at the helm of a great community of people curious about the art of bonsai and interested in being educated in it in a way that isn't bound by the many formal rules of traditional bonsai.

In 2018, Mari and Jerome also started a YouTube channel, The Bonsai Supply, to share bonsai tips for beginners. As of September 2020, they have a large and loyal following and are very active across all social media outlets, building a worldwide bonsai community they call “the bonsai family.”