istyle (TSE:3660) E10: 円-0.13 (As of Dec. 2025)

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Director of Data and Quant Analytics at GuruFocus
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Dr. Charlie Tian is the founder and CEO of GuruFocus.com, a leading global investment research platform established in 2004. With a Ph.D. in physics, Dr. Tian transitioned from science to finance, applying a data-driven, disciplined approach to value investing.

TSE:3660 istyle Inc TSE:3660
79 GF Score
Price 円406.00
GF Value 円455.14
Valuation Modestly Undervalued
! 2 Warning Signs
View Full Analysis

What is istyle E10?

istyle TSE:3660 +0.74% 79 E10 is 円-0.13 as of Dec. 2025. GuruFocus rates TSE:3660 with a GF Score™ of 79/100 and a GF Value™ of 円455.14 (Modestly Undervalued). The stock has 2 warning signs investors should review.

E10 is a concept invented by Prof. Robert Shiller, who uses E10 for his Shiller P/E calculation. E10 is the average of the inflation adjusted earnings of a company over the past 10 years.

istyle's adjusted earnings per share data for the three months ended in Dec. 2025 was 円4.490. Add all the adjusted EPS for the past 10 years together and divide 10 will get our e10, which is 円-0.13 for the trailing ten years ended in Dec. 2025.

Please click Growth Rate Calculation Example (GuruFocus) to see how GuruFocus calculates Wal-Mart Stores Inc (WMT)'s revenue growth rate. You can apply the same method to get the E10 growth rate using E10 data.

As of today (2026-07-14), istyle's current stock price is 円406.00. istyle's E10 for the quarter that ended in Dec. 2025 was 円-0.13. istyle's Shiller PE Ratio of today is .

During the past 13 years, the highest Shiller PE Ratio of istyle was 7714.29. The lowest was 1369.44. And the median was 3838.69.


istyle  (TSE:3660) E10 Explanation

If a company grows much fast than inflation, E10 may underestimate the company's earnings power. Shiller PE Ratio can seem to be too high even the actual P/E is low.

For the Shiller P/E, the earnings of the past 10 years are inflation-adjusted and averaged. The result is used for P/E calculation. Since it looks at the average over the last 10 years, the Shiller P/E is also called PE10.

The Shiller P/E was first used by professor Robert Shiller to measure the valuation of the overall market. The same calculation is applied here to individual companies.

During the past 13 years, the highest Shiller P/E Ratio of istyle was 7714.29. The lowest was 1369.44. And the median was 3838.69.


Be Aware

Shiller PE Ratio works better for cyclical companies. It gives you a better idea on the company's real earnings power.


istyle E10 Related Terms


istyle E10 Historical Data

* Premium members only.

The historical data trend for istyle's E10 can be seen below:

* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD.
* For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.

istyle E10 Chart

istyle Annual Data
Trend Jun16 Jun17 Jun18 Jun19 Jun20 Jun21 Jun22 Jun23 Jun24 Jun25
E10
Get a 7-Day Free Trial Premium Member Only Premium Member Only 0.00 -1.74 -2.32 -0.92 0.36

istyle Quarterly Data
Jun21 Sep21 Dec21 Mar22 Jun22 Sep22 Dec22 Mar23 Jun23 Sep23 Dec23 Mar24 Jun24 Sep24 Dec24 Mar25 Jun25 Sep25 Dec25 Mar26
E10 Get a 7-Day Free Trial Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only 0.07 0.36 -0.06 -0.13 0.00

TSE:3660 vs CASY, WSM, DKS: E10 Comparison

For the Specialty Retail subindustry, istyle's Shiller PE Ratio, along with its competitors' market caps and Shiller PE Ratio data, can be viewed below:

* Competitive companies are chosen from companies within the same industry, with headquarter located in same country, with closest market capitalization; x-axis shows the market cap, and y-axis shows the term value; the bigger the dot, the larger the market cap. Note that "N/A" values will not show up in the chart.


istyle Shiller PE Ratio vs Retail - Cyclical Industry

For the Retail - Cyclical industry and Consumer Cyclical sector, istyle's Shiller PE Ratio distribution charts can be found below:

* The bar in red indicates where istyle's Shiller PE Ratio falls into.


TSE:3660
79GF Score
istyle Inc TSE:3660
E10 is just one metric. See GF Score™, valuation, warning signs, and more.
View Full Analysis

istyle E10 Calculation

E10 is a concept invented by Prof. Robert Shiller, who uses E10 for his Shiller P/E calculation. When we calculate the today's Shiller P/E ratio of a stock, we use today's price divided by E10.

What is E10? How do we calculate E10?

E10 is the average of the inflation adjusted earnings of a company over the past 10 years. Let's use an example to explain.

If we want to calculate the E10 of Wal-Mart (WMT) for Dec. 31, 2010, we need to have the inflation data and the earnings from 2001 through 2010.

We adjusted the earnings of 2001 earnings data with the total inflation from 2001 through 2010 to the equivalent earnings in 2010. If the total inflation from 2001 to 2010 is 40%, and Wal-Mart earned $1 a share in 2001, then the 2001's equivalent earnings in 2010 is $1.4 a share. If Wal-Mart earns $1 again in 2002, and the total inflation from 2002 through 2010 is 35%, then the equivalent 2002 earnings in 2010 is $1.35. So on and so forth, you get the equivalent earnings of past 10 years. Then you add them together and divided the sum by 10 to get E10.

Please note that we use the CPI data of the country/region where the company is headquartered. If the CPI data for that country/region is not available, then we will use the CPI data of the United States as default.

For example, istyle's adjusted earnings per share data for the three months ended in Dec. 2025 was:

Adj_EPS= Earnings per Share (Diluted) /CPI of Dec. 2025 (Change)*Current CPI (Dec. 2025)
=4.49/113.0000*113.0000
=4.490

Current CPI (Dec. 2025) = 113.0000.

istyle Quarterly Data

per share eps CPI Adj_EPS
201603 4.360 97.900 5.032
201606 3.910 98.100 4.504
201609 2.980 98.000 3.436
201612 4.890 98.400 5.616
201703 6.250 98.100 7.199
201706 3.670 98.500 4.210
201709 5.140 98.800 5.879
201712 5.670 99.400 6.446
201803 3.450 99.200 3.930
201806 2.860 99.200 3.258
201809 2.610 99.900 2.952
201812 -1.930 99.700 -2.187
201903 -0.220 99.700 -0.249
201906 -8.740 99.800 -9.896
201909 -3.570 100.100 -4.030
201912 -57.530 100.500 -64.685
202003 -4.315 100.300 -4.861
202006 -11.614 99.900 -13.137
202009 -4.290 99.900 -4.853
202012 -7.380 99.300 -8.398
202103 -8.750 99.900 -9.897
202106 24.785 99.500 28.148
202109 -0.730 100.100 -0.824
202112 -7.711 100.100 -8.705
202203 -0.240 101.100 -0.268
202206 0.680 101.800 0.755
202209 1.220 103.100 1.337
202212 -1.880 104.100 -2.041
202303 0.744 104.400 0.805
202306 3.317 105.200 3.563
202309 1.470 106.200 1.564
202312 4.040 106.800 4.275
202403 4.456 107.200 4.697
202406 4.837 108.200 5.052
202409 5.120 108.900 5.313
202412 4.270 110.700 4.359
202503 5.600 111.100 5.696
202506 4.740 111.700 4.795
202509 5.340 112.000 5.388
202512 4.490 113.000 4.490

Add all the adjusted EPS together and divide 10 will get our e10.

Frequently Asked Questions Learn more about E10 →
What does a E10 of 円-0.13 mean?
istyle (TSE:3660) has a E10 of 円-0.13 as of Dec. 2025. E10 represents the company's inflation-adjusted earnings per share over a 10-year period. View historical data on istyle and its competitors.
Is istyle's E10 too high?
istyle's current E10 is 円-0.13. Overall, istyle has a GF Score™ of 79/100 and is considered Modestly Undervalued, reflecting its overall financial health beyond just this single metric.
How does istyle's E10 compare to CASY and WSM?
istyle's E10 of 円-0.13 can be compared against companies in the Retail - Cyclical industry. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good E10 for a Retail - Cyclical company?
A good E10 depends on the Retail - Cyclical industry context. However, E10 should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Use the industry distribution chart on this page to see where any company falls relative to its peers.
What does a high E10 mean?
A high E10 can signal that a stock is expensive relative to its fundamentals. E10 represents the company's inflation-adjusted earnings per share over a 10-year period. View historical data on istyle and its competitors. istyle's current E10 is 円-0.13. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is istyle stock overvalued right now?
Based on GuruFocus' analysis, istyle (TSE:3660) is currently considered Modestly Undervalued. The stock's GF Value™ is 円455.14, compared to a current price of 円406.00 — trading 10.8% below its estimated fair value. The current E10 is 円-0.13. istyle's overall GF Score™ is 79/100 with 2 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is E10 calculated?
E10 is calculated from a company's financial statements. For istyle (TSE:3660), the current E10 is 円-0.13 as of Dec. 2025. GuruFocus calculates this using data sourced from SEC filings and annual reports. See the calculation section and 30-year financial data on this page for the full breakdown.

Is istyle (TSE:3660) Overvalued in 2026?

Based on GuruFocus' analysis, istyle stock appears to be undervalued. The current stock price of 円406.00 is trading 10.8% below its estimated GF Value™ of 円455.14. GuruFocus considers istyle to be Modestly Undervalued.

Key valuation signals for TSE:3660:

  • E10: 円-0.13
  • GF Value™: 円455.14 vs. price of 円406.00 (10.8% below fair value)
  • GF Score™: 79/100 with 2 warning signs

No single metric tells the full story. See the TSE:3660 stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.


istyle Business Description

Other Exchanges IY5:Germany
Address 34F ARK Mori Building, 1-12-32, Akasaka, Minato-ku, Tokyo, JPN, 107-6034
istyle Inc is engaged in the operation of cosmetics portal Website under the name @cosme. The company operates its business through Media, Electronic Commerce and Store segment. The Media segment involves in the provision of various services including Internet advertising services, such as response advertisings, branding advertisings and affiliate advertisings. The Electronic Commerce segment is engaged in the purchase and sale of cosmetics, quasi drugs, health foods through operating cosmetics online shopping site and the Store segment is involves in the plan and development of cosmetics retail business categories, and the operation of cosmetics retail stores.
79GF Score

Get the complete analysis for TSE:3660

E10 is just one metric. See GF Value™, 30-year financials, guru trades, warning signs, and more.

円406.00
Price
円455.14
GF Value