Koishi's Fishing Journal is an indie casual simulation game built as a Touhou Project fan title. It places Koishi Komeiji on the player's desktop, where she fishes idly while the user works, studies, or steps away. The experience centers on passive collection, occasional management, and steady progression through fish and merfolk varieties.
Gameplay
The core loop revolves around Koishi casting a line in a small desktop window. She continues fishing without constant attention, returning catches that range from common fish to rarer merfolk and the highest-tier mermaids. Players return periodically to review the haul, then convert ordinary fish into cooking ingredients or use merfolk items for premium dishes. These dishes go on sale in a shop, generating earnings that fund upgrades to rods, bait, or other tools. Better equipment raises the chance of encountering uncommon species, which in turn expands the species collection and improves shop profits. The system rewards consistent short check-ins rather than long sessions, fitting the relaxed desktop format.
Game Modes
The game operates as a single-player idle experience with no separate competitive or multiplayer modes. Progression unfolds through the ongoing fishing cycle, species discovery, cooking, and shop management. All activity stays within the desktop window or a simple interface for inventory and upgrades. Players advance by filling the collection, unlocking rarer catches, and scaling earnings, with the entire loop designed around minimal active input once Koishi is set to fish.
Key Mechanics and Progression
Fishing runs automatically once started, influenced by time away from the game. Catches include standard fish usable right away in recipes and special merfolk ingredients that enable higher-value dishes. The collection system tracks every species found, encouraging repeated play to complete the roster. Shop sales convert prepared food into currency for targeted upgrades that improve catch rates and rarity. This creates a steady feedback loop where earnings support better fishing, which yields better ingredients, which support stronger sales.
Is It Worth Playing?
Koishi's Fishing Journal suits players who enjoy low-pressure idle simulation titles and Touhou fan content. Its desktop format allows background activity during other tasks, with short management sessions for cooking and selling. The focus on collection and incremental upgrades provides clear goals without demanding constant focus. As an unreleased title scheduled for Q4 2026, it currently has no player reviews or long-term update history, so expectations should rest on the described idle fishing and shop loop. Those seeking a calm, collectible-driven experience with minimal time commitment will find the mechanics align with that style.