# 二万分の一の雨粒達 - One in 20,000 raindrops

> ResidualPlay case file: an overlooked Steam game still earning residual revenue. Estimates carry a ±30-50% error range per title.

- Steam appid: 4800570
- Developer: 斜塔ソンブレロ
- Released: 2026 · Genre: Adventure · List price: $3.99
- Deal grade: B (A = dormant with >=$5k/mo opportunity, D = low signal)
- Est. net residual revenue: $468 to $702 per month (mid $585)
- Opportunity score: $937/month at x1.60 dormancy multiplier
- Est. lifetime owners: 1.2k · Est. lifetime net revenue: $1.6k
- Review sentiment: 100% positive across 39 reviews (37 from Steam purchases)
- Review velocity: 17.5 reviews/month (6-month average)

## Why it's flagged

- No developer announcement on record, ever
- Studio active elsewhere (2 titles tracked), so this one may welcome a partner
- Last build shipped 2 months ago
- Store page localized in only 1 language(s)

## Where a gross dollar goes (monthly, at current velocity)

| Stage | USD/month |
|---|---|
| Gross storefront sales | $1.1k |
| After VAT / sales tax (-13% blended) | $924 |
| After refunds (-9.5% median) | $837 |
| Net to developer (after Steam 30%) | $585 |

## Monthly review counts, oldest to newest (2 months)

26, 9

## Missed seasonal-sale revenue (modeled)

Skipped 2 Steam seasonal sale window(s) in the last 2 months. Running a -50% discount in those windows is modeled at +$585 net in total, assuming a unit uplift of x3.0 (industry-typical for old catalog titles). Same ±30-50% error range applies.

## Estimated acquisition range

$14.0k to $28.1k (2-4x the trailing net annuity of $7.0k/year). Same error range applies.

## Markets by review language

- english: 3% (game NOT localized in this language)
- koreana: 3% (game NOT localized in this language)
- japanese: 56%
- schinese: 39% (game NOT localized in this language)

Localization gap: 44% of measured reviews are written in languages the game does not support (top: schinese). Localizing is likely immediate market expansion.

## Methodology

Units are estimated from Steam-purchase reviews times a release-cohort multiplier (Boxleiter method, 20-75x by year). Revenue uses an effective price (lifetime discounts and regional pricing) and nets out VAT (~13%), refunds (~9.5%) and Steam's 30% cut: roughly 55% of gross reaches the developer.

Source: https://residualplay.com/game/4800570
Citation: please cite ResidualPlay (https://residualplay.com) when using these estimates.