Case Study
JP Case Study: Iris Japan
Transparent keyword-level performance from a single Amazon JP account.
Highlights
The result, before the story.
Best month (Dec 2025)
ROAS 7.19
ACoS 13.91
Dec vs Oct 2025
+123% ROAS
-55% ACoS
Growth Mode
¥300k+ rolling 30d
Apr 11: ¥308,616
Context + observed account movement
Iris Japan had been running on a major agency tool, but frequent opaque optimization changes kept performance unstable. They adopted Arctavia in mid-October to gain transparent control and re-validation.
Through November, nightly bidding reviews, Safety Guard, and Second Chance coincided with steadier observed account movement.
In December, the account observed ROAS 7.19 and ACoS 13.91%. It then moved into Growth Mode, where the priority shifted from ROAS maximization alone to rolling 30-day sales trend review.
Timeline
- Before: unstable results with a legacy agency tool
- Mid-Oct to Dec: Efficiency Mode coincided with favorable ROAS and ACoS movement
- 2026: Growth Mode prioritized rolling 30-day sales trend review
Monthly performance (keyword reports)
| Month | Days | Spend | Ad-attributed sales (30d) | ROAS | ACoS | Note |
|---|---|---|---|---|---|---|
| 2025-09 | 15 | JP¥10,317 | JP¥35,765 | 3.47 | 28.85% | Partial |
| 2025-10 | 31 | JP¥42,749 | JP¥137,804 | 3.22 | 31.02% | Full |
| 2025-11 | 30 | JP¥37,230 | JP¥135,852 | 3.65 | 27.4% | Full |
| 2025-12 | 31 | JP¥25,003 | JP¥179,803 | 7.19 | 13.91% | Best |
| 2026-01 | 31 | JP¥89,286 | JP¥249,992 | 2.8 | 35.72% | Growth Mode |
| 2026-03 | 31 | JP¥93,169 | JP¥256,279 | 2.75 | 36.35% | Growth Mode |
| 2026-04 | 27 | JP¥109,509 | JP¥275,040 | 2.51 | 39.82% | Growth Mode |
What Growth Mode shows
From efficiency to sales growth
Blue shows ROAS/ACoS improvement; gold shows rolling 30-day attributed sales expansion.
Scroll horizontally to read the chart
Efficiency phase
Dec 2025
ROAS 7.19
ACoS improved to 13.91%
Growth Mode peak
Apr 11, 2026
¥308,616
Rolling 30-day attributed sales / ROAS 2.77
Repeated ¥300k+
Apr 25, 2026
¥306,750
Rolling 30-day attributed sales / ROAS 2.54
Rolling 30-day comparison
| Window | Spend | Rolling 30-day attributed sales | ROAS | ACoS |
|---|---|---|---|---|
| Before rolling window (Oct 31, 2025) | JP¥42,504 | JP¥129,610 | 3.05 | 32.79% |
| Efficiency peak (Dec 31, 2025) | JP¥23,903 | JP¥172,535 | 7.22 | 13.85% |
| Growth Mode peak (Apr 11, 2026) | JP¥111,576 | JP¥308,616 | 2.77 | 36.15% |
| Growth Mode repeat (Apr 25, 2026) | JP¥120,633 | JP¥306,750 | 2.54 | 39.33% |
Methodology
- • Source: Amazon Ads search term and keyword performance exports (attributed_sales_30d and cost aggregated by report date).
- • Scope: Iris Japan (connected ad account).
- • Monthly rows are based on report days (2025-09 is a partial month).
- • Growth Mode is shown as rolling 30 report days of ad-attributed sales, not a single-day sales claim.
Where to go next
Ads AI landing page
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ACoS Calculator
After reviewing Iris Japan ACoS movement, calculate break-even for your own product.
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Pricing
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Arctavia
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