---
title: "RUMAHSAKU CORP. — Publisher Overview"
type: publisher
publisher: "RUMAHSAKU CORP."
publisher_slug: "rumahsaku-corp"
canonical_url: "https://marlvel.ai/publishers/rumahsaku-corp"
last_updated: 2026-05-19T23:13:04.553Z
source: Marlvel.ai
license: CC-BY-NC-4.0
citation: "Marlvel.ai — RUMAHSAKU CORP. Publisher Overview"
---
# RUMAHSAKU CORP. — Publisher Overview

> Providing specialized exam preparation tools for technical and professional certification candidates. Helping users master specific industry skills through structured mock exams and practice modules.

- **Publisher:** RUMAHSAKU CORP.
- **Overview generated:** 2026-05-19
- **License:** CC-BY-NC 4.0

## Executive summary

Rumahsaku Corp operates as a high-volume, niche-focused publisher that targets the fragmented Japanese professional certification market. Their strategy relies on rapid deployment of single-purpose study apps, effectively capturing long-tail demand for specific technical and vocational exams that larger educational platforms often overlook. The primary tension in their model is the high ratio of abandoned or legacy titles, suggesting a 'test-and-discard' approach to product development rather than long-term lifecycle management for individual apps.

## Publisher DNA

- **Primary focus:** Professional certification and technical exam preparation apps
- **Scale:** studio
- **Target audience:** Working professionals and job seekers in Japan preparing for national trade skills, safety, and industry-specific certifications.

## Portfolio momentum

- **Velocity:** maintenance
- **Active apps:** 2
- **Abandoned apps:** 28
- **Last major release:** 2 days ago

With only 2 releases in the last 6 months and a high volume of abandoned titles, the publisher is currently in a maintenance phase for the majority of its catalog.

## Aggregated portfolio metrics

- **Total reviews (all apps):** 33
- **Weighted rating:** 4.03 / 5
- **Apps in portfolio:** 30

## Category breakdown

| Category | Apps | Share |
| :--- | :--- | :--- |
| Uncategorized | 28 | 93.3% |
| Education | 2 | 6.7% |

## Top apps

- **SCOA　試験対策** — Most popular title with 21 reviews and a 4.52 rating.
- **消防設備士1類　試験対策** — Second most popular title with 12 reviews.
- **仕上げ技能検定2級　学科試験対策** — Representative of their technical trade certification focus.
- **在宅看護指導士　試験対策** — Representative of their healthcare-related certification focus.
- **CUBIC　基礎能力検査対策** — Representative of their corporate aptitude test preparation focus.

## Signature patterns

- Consistent paid-upfront pricing model across all titles.
- Highly specialized content tailored to specific Japanese national and industry exams.
- Minimalist UI focused on question banks and mock exam simulations.
- High volume of niche titles with low individual review counts.

## Bottom line

Rumahsaku Corp is a niche publisher that successfully leverages the long-tail of professional certification needs in Japan. Their ability to maintain a high-rated flagship app suggests a solid core product, though the broader portfolio requires more consistent updates to remain relevant.

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© 2026 Marlvel.ai | [Publisher apps index](https://marlvel.ai/api/llm/publishers/rumahsaku-corp) | [Methodology](https://marlvel.ai/api/llm/methodology)
Data licensed under CC-BY-NC 4.0.

---
© 2026 Marlvel.ai | [Full publisher profile](https://marlvel.ai/publishers/rumahsaku-corp) | [Publisher apps index](https://marlvel.ai/api/llm/publishers/rumahsaku-corp) | [Methodology](https://marlvel.ai/api/llm/methodology)
Data licensed under CC-BY-NC 4.0.