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Faster, easier to use, and cleaner cuts than ever before. Cosine makes it possible.

Introducing the “cosine” next-generation razor, jointly-developed by MIZUTANI and Mr. Katsuji Oono, a razor specialist.

Katsuji Oono

“For me, a razor is like a 6th finger that cuts exactly the way I want. I think of it as a tool for customizing each customer’s hairstyle. A razor is essential for developing the style you picture in your mind. If hair design is like engraving, then a razor is similar to a fine chisel used for adding detail. The cosine is a wonderful tool that enables you to develop length, structure, and texture at the same time. This saves time on haircutting, which you can then consider using for other services.”

Mr. Oono’s expertise and knowledge are evident in many features of the cosine, such as its perfect weight and balance, and rotation so smooth you’ll want to try it out for yourself. The unique design has an organic shape, and the product itself is a crystallization of the passion and ingenuity of a razor specialist. Using the cosine is like nothing else. Try one out for yourself and you’re sure to fall more in love with it each time. Mr. Oono has held over 2,000 seminars over the last 30 years, and many stylists have been influenced by his ideas. He continues to work in a salon even now, all while engaging in nationwide educational activities for stylists.


  • Triple role:
    You can take care of all 3 elements length, structure, and texture with just one tool.
  • Cut with just its weight:
    No damage to hair, because it cuts with just the weight of the body (of the tool).
  • Easy changing:
    The next-generation magnetic holding system enables quick blade changing.

Easier to Use

  • Four different grips:
    Easy to control “cut, volume, thin” only changing the razor holding position.
  • Center of gravity in hand:
    When gripping it with the weight centered in your hand, it gives solid control for precise cutting.
  • Principle of pendulum:
    Because we’ve purposefully moved the center of gravity outward, the razor swings smoothly back and forth like a pendulum.

Cleaner Cuts

  • Nuance in hair ends:
    Gives a soft finishing touch to hair, for ends like the tip of a brush.
  • Multi-talented:
    Can be used for a variety of effects, widening the breadth of techniques at your disposal.
  • Even works for short:
    Gives a soft finish even for short haircuts and men’s hair.

4 different positions and techniques of Cosine

  • Regular Hold:
    This is the recommended grip for choosing and adjusting length. With short strokes, you can create an even cut with all hair in the same layer, and with long strokes, it’s easy to add layers to a hairstyle. The cosine provides easy control over layers, so you can cut the layers you’re picturing all at once.
    Mizutani Cosine Regular Hold
  • Pencil Hold:
    Using this grip for cutting enables easy bundled looks and volume control. Also, because you can make fine and detailed strokes, it’s good for tight turns. Like drawing with a pen, you can style the crown and cape freely, and it’s also easy to cut the tips to different lengths. As a result, this grip is well-suited for a style with gentle lines around the face.
    Mizutani Cosine Pencile Hold
  • Peel Hold:
    Snap the grip in front of your wrist, like you’re peeling a potato, and cut. Up cuts for short styles are easy to do with this grip, and you can quickly thin hair volume to your liking.
    Mizutani Cosine Peel Hold
  • Swing Hold:
    The ideal weight and balance makes the razor easy to swing, enabling thinning with a randomized pitch. It’s also easy to adjust inside hair volume and feeling with this grip, and it can be used to give a soft and fluffy finish to your haircuts, almost like you’ve added a cushion of air inside.
    Mizutani Cosine Swing Hold

The magnetic holding system enables easy blade changing.

Mizutani Cosine Balde change