# コイカツ！ / Koikatsu Party

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

- Steam appid: 1073440
- Developer: ILLUSION
- Released: 2019 · Genre: Simulation · List price: $59.99
- Deal grade: A (A = dormant with >=$5k/mo opportunity, D = low signal)
- Est. net residual revenue: $3.4k to $5.2k per month (mid $4.3k)
- Opportunity score: $11.2k/month at x2.60 dormancy multiplier
- Est. lifetime owners: 212.2k · Est. lifetime net revenue: $2.7M
- Review sentiment: 91% positive across 5732 reviews (5304 from Steam purchases)
- Review velocity: 13.3 reviews/month (6-month average)

## Why it's flagged

- Developer silent for 3.1 years
- Studio inactive: no public activity across 4 tracked titles
- Last build shipped 5.4 years ago
- Store page localized in only 3 language(s)
- No Steam discount in 3.5 years (deepest tracked: -20%)

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

| Stage | USD/month |
|---|---|
| Gross storefront sales | $7.8k |
| After VAT / sales tax (-13% blended) | $6.8k |
| After refunds (-9.5% median) | $6.1k |
| Net to developer (after Steam 30%) | $4.3k |

## Monthly review counts, oldest to newest (24 months)

18, 13, 22, 17, 28, 19, 10, 15, 23, 22, 22, 11, 17, 12, 18, 11, 17, 20, 15, 11, 11, 16, 10, 17

## Missed seasonal-sale revenue (modeled)

Skipped 12 Steam seasonal sale window(s) in the last 24 months. Running a -50% discount in those windows is modeled at +$31.9k 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

$103.2k to $206.3k (2-4x the trailing net annuity of $51.6k/year). Same error range applies.

## Analyst notes (AI-assisted)

A 2019 Japanese character-creation and dating-sim from ILLUSION featuring deep 3D customization tools wrapped around minimal visual-novel gameplay.

Koikatsu Party has generated $2.7M lifetime on 212k units despite zero sales velocity in the past 12 months, suggesting a mature niche audience extracting value primarily from the character creator and mod ecosystem rather than first-party content. The $4.3k/mo residual revenue and 91% positive ratio indicate a stable, if quiet, catalog holding. Acquisition makes sense only if a buyer seeks to: (1) monetize the mod ecosystem via a storefront or creator fund, (2) license the engine to other publishers, or (3) launch a premium sequel with live-service cosmetics. Otherwise, watch for a licensing or IP-licensing play by a larger adult-games publisher.

- Most realistic play: licensing
- Risk (market): The title's appeal is heavily dependent on mod content (uncensoring, POV, cosmetics) that ILLUSION does not officially distribute; any acquisition that disrupts that ecosystem will trigger refunds and loss of tail revenue.
- Risk (tech): No developer posts in 37 months; codebase stability and compatibility with future OS/driver versions is unknown.
- Risk (other): Core gameplay loop is acknowledged even by fans as minimal; the title's value is entirely in character creation and social modding, which has limited crossover appeal and high churn risk if monetization shifts.

What players are asking for:
- Official mod marketplace or cosmetic store to monetize player-created content
- New story/dating content and gameplay variety beyond 'give garlic bread to NPCs'
- Built-in uncensoring and POV camera modes to reduce mod dependency
- Performance optimization and newer engine features

Suggested first moves:
1. Audit the mod ecosystem (Discord, GitHub, Nexus Mods) to quantify creator output and revenue potential if formalized; assess whether ILLUSION retains engine rights to license or if existing mods constitute legal encumbrance.
2. Model a cosmetic storefront or creator-fund revenue share against current $4.3k/mo tail to forecast breakeven for a revived community-management team.
3. Contact ILLUSION for asset access and codebase state; if studio is defunct, verify IP ownership and licensing terms to confirm acquirability.

Generated 2026-08-20 from public signals and player reviews. Directional, not diligence.

## 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/1073440
Citation: please cite ResidualPlay (https://residualplay.com) when using these estimates.