A finished BitKoi garden: koi swim in a round pond ringed by stone lanterns, red maples, bamboo, a raked gravel bed and a tea house.

Breed two koi. See what hatches.

Start with one koi and a muddy pond. Pair two grown koi, wait for the egg, and build a garden around them piece by piece.

Play free in your browser Tour the gardens

In-game screenshot · Bamboo and maple garden

Day one

One koi, a muddy pond and 500 credits.

Pick your first koi from eight classics: Kohaku, Showa, Sanke, Ogon, Asagi, Shiro Utsuri, Tancho or Chagoi.

Then pick where your pond sits: bamboo forest, cliffside, tropical jungle, temple woods, mountain vista or night observatory. The setting stays; everything inside the plot is yours to build.

Your starter arrives as a young Tosai. Feed it and it grows into a Nisai, then an Adult, and its colours get sharper on the way.

Your first ten minutes, step by step
The first screen of the game: eight classic koi to choose from, floating over an empty pond.
The first thing you see: choose one of eight classic koi.

Breeding

Two grown koi. One egg. Nobody knows what hatches.

A baby takes from both parents and from grandparents you may never have met. Its pattern starts soft and sharpens as it grows, so you find out slowly what you bred.

Each koi can spawn five times in its life, so every pairing counts. Some bloodlines carry looks you will not see on a starter: a heart mark on the head, scales that glow, eyes that shine in the dark.

Open a card to see the koi swim on its own page. On a phone, tap once to make it swim, then again to open it.

Building

Your garden starts bare.

Open build mode and place pieces where you want them. A potted lily pad costs 25 credits. A stone lantern costs 80. An underwater camera costs 1,000 and lets you watch your koi from below the surface.

Paths, maples, a tea house, a raked gravel bed: the garden in the picture at the top of this page is made from the same kind of pieces.

Build mode on day one: a bare pond with one koi, and a drawer of water pieces with prices: potted lily pad 25, potted lotus 40, stone lantern 80, underwater camera 1,000 credits.
Day one, build mode open.
A finished cliffside garden: a stone-ringed pond, cherry trees, a waterfall, a red bridge over a stream and a tea house.
Later: the Lantern-lit cliffside garden.

Gardens

Six places to put your pond.

Each setting has its own plants, light and landmarks. Open one to look around the live garden. The cliffside garden is pictured above.

Market

Sell what you breed. Buy the koi you are missing.

Your starter needs a partner, so your first trip to the market comes early. List a koi you bred and set your price; for now the game buys it, and the credits are yours. Credits pay for new koi, garden pieces and a second pond.

Open the market
The market: koi portraits with names, variety, life stage and a price in credits, from 196 to 370, each with a Buy button.
The market. Prices follow how rare a koi looks and how grown it is.

Devlog

What changed this week

  1. Six garden settings

    New ponds now start as a bare plot inside a setting you choose. The bamboo, cliffside, tropical, temple, mountain and observatory gardens are all live on the Gardens page.

  2. Day and night

    The pond opens in bright daylight. In View settings you can switch to dusk, night, or your own local time, when the lanterns light up and the koi get sleepy.

  3. Faces you can read

    White rings around the eyes and a carved mouth: now you can read the face of an all-black koi.