Ishizawa Lab's official ingredient page for the Keana Nadeshiko Baking Soda Soap Bar is the shortest you are likely to see for any skincare product. It lists two items: soap base, described as a cleansing ingredient, and sodium bicarbonate, also a cleansing ingredient. That is the complete formula. No fragrance, no preservative, no glycerin, no oils added back. For people tired of long ingredient lists, that simplicity is compelling. It is also exactly why this bar suits some skin types very well and others not at all.
Start with what 'soap base' means. In Japanese labelling, the term covers true soap — fatty acids from plant or animal fats reacted with an alkali. Japanese retailers describe this bar as slowly kettle-cooked over about a week, a traditional method associated with a creamy lather and good quality. Soap is excellent at removing oil, sebum and grime, and it lathers generously. It is also alkaline, typically with a pH around 9 to 10, well above the slightly acidic surface of healthy skin.
Baking soda is the second ingredient, and the reason the bar belongs to the Keana Nadeshiko 'pore princess' line. Sodium bicarbonate is itself mildly alkaline. In the soap, it adds a faint polishing feel and, according to the brand's retail description, helps soften old skin cells and loosen sebum from pores. Its effect in a quick wash is modest. It is a signature more than a treatment.
The packaging is refreshingly unpretentious: a pale blue plastic wrapper printed with bubbles and the line's round mascot, her nose dotted with visible pores. The Japanese text calls it a 'pore soap' for 'cleaning everything', marks it for whole-body use, and promises 'baking soda foam' for skin that feels rough and bumpy. There is no claim of brightening, anti-aging or botanical magic — just a soap for oily, textured skin, sold the way Japanese drugstores have sold practical soaps for decades. That honesty matches the formula. The bar is not trying to be a skincare treatment; it is trying to be a very thorough, very simple wash, and on the right skin it succeeds.
In use, the bar performs as a well-made soap should. Rubbed between wet hands or in a foaming net — the classic Japanese way — it produces a dense, creamy lather. On the face, it feels thoroughly cleansing, and after rinsing, oily skin is left matte and squeaky-clean. On the body, particularly on an oily back or chest, it does the job with no fuss. There is no scent beyond a clean soap smell.
The problem is what the formula does not contain. Most modern cleansers, including soap-based ones, add glycerin, oils or soothing agents to offset the drying effect of alkaline cleansing. This bar has none. Repeated washing with an alkaline, unbuffered soap can raise the skin's surface pH temporarily, strip lipids and increase water loss. Resilient oily skin generally shrugs this off. Dry, sensitive, eczema-prone or rosacea-prone skin often responds with tightness, flaking or redness. Anyone using retinoids or acids will likely find it too much in combination.
That is the heart of the minimalist trade-off. Short ingredient lists reduce the chance of reacting to a particular preservative or fragrance, which is a real benefit for some people with allergies. But 'fewer ingredients' is not the same as 'gentler'. Here, both ingredients point in the same direction — alkaline and cleansing — with nothing pointing the other way.
It is also worth managing expectations about pores. The bar cleans surface oil well, so noses may look less shiny and feel smoother. It will not remove established blackheads, which form deeper in the follicle and respond better to salicylic acid or retinoids used consistently.
There are practical considerations, too. A bar without preservatives stays stable because soap itself is hostile to microbes, but it needs to dry between uses; leaving it in standing water softens it and shortens its life. A draining soap dish helps. Foaming nets, cheap and common in Japan, stretch the bar and produce a finer lather that needs less rubbing.
English-language reviews are scarce, although the soap has long been sold in Japanese drugstores as part of a popular line. The US price from an import retailer is around eighteen dollars for 155g — considerably more than in Japan — which makes it an expensive bar of soap by American standards, even if it lasts a couple of months on the face alone.
How to use it: wet your hands and the bar, work up a thick lather (a foaming net makes this easy), apply the foam rather than the bar to your face, massage briefly, and rinse thoroughly with lukewarm water. Follow immediately with a hydrating lotion or toner and a moisturiser. For oily skin, once or twice a day is fine; for combination skin, once a day, perhaps only in the evening, is usually better.
The verdict is clear. If you have oily, resilient skin and appreciate an ultra-minimal, fragrance-free, preservative-free cleanser, this is a satisfying, honest bar that does one job well. If your skin is dry, sensitive or reactive, the same simplicity works against you, and a buffered, low-pH cleanser will serve you far better.
