Natural Indigo Dye Studio
in Awaji Island, Japan

About us

We are Sally and Junichi, from the UK and Japan. We have lived on Awaji Island since 2015 and opened the AiAii shop and workshop in 2020. Awaji Island is in the Kansai region of Japan, close to Osaka and Kobe.

At first we were interested in pattern making with various shibori techniques. Gradually we got deeper into the traditional Japanese methods; now we dye with natural fermented indigo, called sukumo.

From 2021 we started to grow our own organic leaves (persicaria tinctoria) from seed in order to make our own sukumo. This is a lengthy annual process that stretched for 18 months from sprinkling the first seeds to dyeing fabric with that dye.

We love how modern some of the results of the ancient methods appear, and we also like inventing our own apparatus and techniques, or borrowing and blending with indigo dyeing methods from around the world.

Natural indigo vat

We use the traditional Japanese method of making up a vat with ‘sukumo’. Indigo leaves (persicaria tinctoria, or ‘tade-ai’) are harvested and seperated from the stalks, which contain no blue. They are sun-dried in the middle of the Japanese summer which takes about 1 full day. After 2 or 3 harvests spread over the summer, in the autumn, the collected dried leaves are fermented into a sort of compost called 'sukumo'. A pile of leaves is mixed with water and left for 4 days, in which it becomes naturally hot and starts to break down. Over the following 3 months new water and leaves are added every 4 days.

When the time comes to make up a new vat we use hot, high alkaline water, made from wood ash, and massage it together with the sukumo. It usually takes a few days before the colour emerges. We add shell lime ‘kai bai’ and wheat husk gruel when necessary, to balance the PH and feed the micro-organism community. We tend to use a vat for more than one year before the colour gradually decreases to a very pale blue, and we return the sludge at the bottom to our indigo field.

As we only use natural ingredients our products are gentle on the environment and on our bodies.

The blues we garner from natural indigo are deeply complex and have a range that is hard to achieve from chemical equivalents.

Indigo Dye Workshop

Natural indigo workshops at AiAii in English

We enjoy showing and sharing the magic of natural indigo with people from all over the world in Japanese and English. We can discuss and demonstrate all kinds of techniques, depending on your interests and experience.

We also love to help you refresh your old clothes, or 2nd hand finds from thrift stores. You can bring your old sundress, printed white T-shirt, baby clothes, scarf or pillow case. Get as much wear out of your clothes as possible! Just make sure it's 100% cotton or linen.


AiAii is accessible by public transport.Sumoto Bus Center is a 5 minute walk. There are direct buses to the bus center from Maiko train station, Kobe Sannomiya, and Osaka.

2-3-19 Kaigandori
Sumoto city
656 0022

We are usually open on Fridays and Saturdays from 10-5pm but it is best to check on instagram or give us a call to make sure. We also happily open the shop by appointment if you let us know in advance.

Workshops can usually be scheduled from Monday-Saturday