Worn close. Made to last.
Tech Core Nex Wave is a Tokyo-based boutique designing swimwear and lingerie for women who want something considered. Cut from European fabrics, finished by hand in our Daikanyama atelier.
A bit more
Today Tech Core Nex Wave produces two collections a year. A summer swimwear line and a winter lingerie line. Plus a small number of made-to-order pieces for clients who want something specific. The fabrics are still sourced from the same Lyon mill, with a second supplier in Porto added in 2023 for a particular stretch-lace we could not find anywhere else. Haruka still cuts the patterns herself. The team is five people. That is not a constraint; it is a choice.
I came back to Tokyo to make the thing I could not find here.What we stand for
European fabrics, sourced directly
We work with two mills in Lyon and one in Porto. The fabrics arrive undyed; we colour them in small batches using water-based dyes at our Daikanyama studio. Nothing is ordered in bulk until we know it holds its shape after salt water.
Hand-finished seams
Every garment passes through the hands of one of our three in-house seamstresses before it leaves the atelier. The interior seams are bound in a narrow silk tape. You will not see it, but you will feel the difference after a full day of wear.
Sizing that starts from the body
We fit every new silhouette on three different body proportions before it enters the collection. Our size range runs from XS to XL, and we offer a complimentary fit consultation by appointment at the boutique.
No seasonal overproduction
We produce in runs of 40 to 80 units per style. When a style sells out, it is gone. We do not restock to chase a trend; we revisit a silhouette only when we have something new to say about it.
News & Announcements
- 012026-06-01
How to care for recycled polyamide swimwear
Recycled polyamide is a better fabric than virgin nylon in almost every respect: it holds its…
- 022026-04-15
Choosing between silk and microfibre for everyday lingerie
The question comes up in almost every fitting appointment: should I choose silk or microfibre? The…
- 032026-03-10
How swimwear sizing works in Japan, and why it matters
Sizing in swimwear is less standardised than in ready-to-wear clothing, and the gap between…
Find the right piece for you
Answer three questions and we will point you toward the styles most likely to suit your needs. A gift, or something to wear every day.
Meet the maker
Haruka Nishimoto grew up in Kyoto and moved to Paris at twenty-three to study pattern-cutting at the Chambre Syndicale de la Couture Parisienne. She spent eight years as a pattern-cutter for a French lingerie house in the 2nd arrondissement, then two seasons assisting a swimwear designer in Barcelona before returning to Tokyo in 2017. She founded Tech Core Nex Wave in Daikanyama in the spring of 2018 with seven pieces and one assistant. She still cuts every pattern by hand. On Saturday mornings, when the atelier is quiet, she swims at the Meguro pool before opening the boutique.
Common questions
Q.Do you ship internationally?
Yes. We ship to most countries via Japan Post EMS or DHL Express, depending on the destination. Shipping is calculated at checkout. We pack every order in our rigid cotton-covered box regardless of destination. Nothing arrives in a poly mailer.
Q.What is your return policy?
We accept returns within 14 days of delivery for unworn, unaltered pieces with the original tags attached. Swimwear must have the hygiene liner intact. We do not charge a restocking fee. Custom atelier orders are non-returnable, but we will work with you if something is not right.
Q.How do I know my size?
Our size guide is on every product page, with measurements in centimetres. If you are between sizes or unsure, book a complimentary fitting appointment at the Daikanyama boutique, or email us at us with your measurements and we will advise. We would rather you get the right size than the wrong one.