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Mitsuteru Ozaki, outdoor gear craftsman

Playing and creating, forever a boy at heart



Ultralight backpacking, fishing, stream climbing, bikepacking, fastpacking, and more—for an all-around superstar in outdoor circles, look no further than Mitsuteru Ozaki, aka Jackie Boy Slim. His independent brand Jindaiji Mountain Works (JMW), now in its fourth year, is best known for minimal, sophisticated ultralight backpacking gear like tarps, hammocks, and cookers. But the first item released was actually a fishing product called the Packman Vest.

Jackie grew up stream fishing and went on to expand his fishing experience further in the seas, the rivers, and the mountains. After becoming a devoted ultralight hiker in his thirties, he once took a break from fishing but later rekindled his passion, and now spends his time angling in the clear streams of Yamanashi Prefecture and in the bay off the shore of the Seisho area of Kanagawa Prefecture, a short way from his studio in Takao.

As broad as his range of outdoor activities may be, fishing is a crucial part of Jackie’s identity. The idea for the Packman Vest came from his unique experience and mindset as an angler.

“The vest was inspired by the front pack that I used for sea bass wading* twenty years ago. All the products today are big and bulky with buoyancy features, since life jackets are mandatory, but I liked the simple front packs. So I decided to downsize my favorite design for use in mountain streams, and that became the Packman Vest. It could be worn together with a large backpack because it didn’t interfere with the shoulder harnesses, and it worked for both day trips and overnight camping. I kept waiting for a product like that to come out, but it never did, so I made it myself.”

In an outdoor industry where creation is driven by marketing, lately even at independent brands, JMW continues to present purely original products. The main creative criterion, Jackie says, is whether or not an item makes him feel excited.

“I make what I like for myself, first and foremost, and so that I can share what I think is cool and convenient with like-minded friends. Many of the products released at JMW aren’t made anywhere else. If a great product were already available, we could all simply use that, and there’d be no need for JMW to make it, right? I’m not interested in making products that sell. I just want to make enough money so that I can be happy.”

Jackie’s creative spirit is self-sufficient. His work isn’t dictated by sales, and in a sense, this is consistent with his outlook on fishing. That is, throughout the years he has been a passionate angler, his fishing spirit has never been dictated by the catch.

In Omaezaki, Shizuoka Prefecture, when we stopped by a fishing tackle shop for surf fishing the next morning, Jackie bought a curious lure with a funny face and bizarre colors. I asked why he chose that one. “I like that it looks silly. Wouldn’t it be fun if I actually caught a fish using this?” he said with a fresh, youthful smile.

“With fishing, I don’t expect to make a catch to begin with, so whether I make a catch or not, it’s always fun. Each time I cast the line, I use my imagination and picture a fish biting, and if it doesn’t, I’ll keep casting again and again, hundreds of times a day. What could be more fun? It’s a game for romantic fools! Not that I’d complain if I did make a catch. But it’s casting the rod hoping that I might get a hit this time that makes me happy. Fishing isn’t about fulfilling a dream, you see. It’s about dreaming a dream. For me, they’re all the same—fishing, product design, and romance. It isn’t the outcome that counts. It’s playing by my rules and doing it in style that makes me a winner. That’s where I get my satisfaction.”

Forever a boy at heart, Jackie will go on trekking in the hills, fishing in the streams, and doing his homework of making JMW products, all for the joy of the outdoors, and most of all, for his own happiness.

* Fishing done while standing in the water wearing a pair of waterproof overalls called waders

Mitsuteru Ozaki, aka Jackie Boy Slim, outdoor gear craftsman
Mitsuteru Ozaki is an outdoor gear craftsman born in 1971. After eight years in the production and development of ultralight backpacking gear at the ultralight shelter maker Locus Gear, he went independent in 2018 and launched Jindaiji Mountain Works (JMW). Jackie currently works from his studio in the foothills of the Takao area of Tokyo.

A journey into the sea, peaks and rivers of Shizuoka focused on "fishing" and "fish." Guests for this trip are Shizuoka-born illustrator Jerry Ukai and outdoor craftsman Mitsuteru Ozaki, aka Jackie Boy Slim.