Koshi means “base strength” in this Miroshaki Aquascaping Dictionary. The lower strength or waist of a form. It comes from bonsai language and is useful for reading roots, trunks, branches and old natural forms.
Japanese: 腰 Romaji: Koshi
Meaning of Koshi
Koshi is explained here in simple English so beginners can use the word without feeling lost. In Miroshaki style, the term is not only a translation. It is a small way to look more carefully at nature underwater.
How Koshi Helps in Aquascaping
Use it to judge whether a stone or wood piece feels grounded. This can help when you choose stones, place wood, create open space, plant moss, or wait for the aquarium to grow into a more natural balance.