Monster-raising SLG "Mamom King," produced by YOSHINAMARU, to be released on December 11 for PC and Switch
Note: the original Japanese article can be found at:
https://www.4gamer.net/games/950/G095035/20251001051/
Editorial Department: Igarashi | 2025/10/01 10:59 (UTC)
LiTMUS announced today (October 1, 2025) that its new title developed in collaboration with YouTube content creator Yoshinama, “Mamong King,” will be released on December 11 for PC and Nintendo Switch. The price is 1,480 yen (tax included).
This title is a completely new original game produced by Yoshinama, featuring the raising of unique monsters called “Mamons” with the goal of making them the strongest. The battle system uses a 1-on-1 round-based command format where strategy and player judgment determine victory—not just raw power.
Mamons can be summoned via gacha and feature unique traits such as different lifespans and abilities. A total of 37 distinct Mamons are available. In addition to regular training at the base, players can undertake “Expeditions”—a board game-style system where they roll dice to progress—and face various events and challenges along the way.
Thumbnail image for Gallery No. 003 / Monster-raising SLG “Mamong King” produced by Yoshinama, set to launch December 11 on PC/Switch Thumbnail image for Gallery No. 004 / Monster-raising SLG “Mamong King” produced by Yoshinama, set to launch December 11 on PC/Switch
To coincide with the announcement, a promotional video featuring Yoshinama himself introducing the game has been posted—those interested are encouraged to check it out.
Official X of “Mamong King”
Monster-raising simulation game ‘Mamong King’ set for winter release! A brand-new title produced by popular YouTuber Yoshinama
LiTMUS Co., Ltd. (Headquarters: Minato-ku, Tokyo; President & CEO: Takashi Kuwamura) is pleased to announce the upcoming release of its new title, Mamong King, developed in collaboration with renowned YouTube content creator Yoshinama—whose channel has over 1 million subscribers—for Nintendo Switch and Steam. The game launches on December 11, 2025 (Wednesday). This monster-raising simulation game invites players to summon monsters known as “Mamons” from another world, raise them, and battle toward becoming the ultimate ‘Mamong King.’ To mark today’s announcement, we are releasing the official key visual for the first time. Additionally, we have launched an official X (formerly Twitter) account dedicated to delivering updates—please stay tuned for more news.
Yoshinama’s announcement video for this game:
https://youtu.be/kjHzWHWj-4Q?si=wEpdKzUrExd91Jmv
We’ve released a video introduction to the game by Yoshinama himself. Be sure to watch it and discover firsthand why he’s so passionate about this project.
Game Overview: Mamong King
A monster-raising simulation game aiming for the ultimate ‘Mamong King’
In this game, players summon monsters called “Mamons” from another world, nurture them through training and battles, and strive to become the strongest—earning the title of ‘Mamong King.’ The battle system features a 1-on-1 round-based command format where strategy and player decision-making are crucial. Victory depends not on brute strength alone but on skillfully managing your Mamons’ stats and mastering their diverse abilities.
Thumbnail image for Gallery No. 005 / Monster-raising SLG “Mamong King” produced by Yoshinama, set to launch December 11 on PC/Switch Thumbnail image for Gallery No. 006 / Monster-raising SLG “Mamong King” produced by Yoshinama, set to launch December 11 on PC/Switch Thumbnail image for Gallery No. 007 / Monster-raising SLG “Mamong King” produced by Yoshinama, set to launch December 11 on PC/Switch
Introducing some of the standout Mamons!
Mamons can be summoned via gacha, with 37 unique types available—each differing in lifespan and abilities.
Here are three featured examples:
Leorf
A courageous beastman known as a “samurai.” He wields a mystical blade that grows stronger alongside him, and is proud to fight in one-on-one duels—master of an ancient fighting style.
Keymyu
The most widely recognized Mamon due to its cute appearance. Though timid by nature, it becomes fast and fierce under pressure—revealing its true strength when cornered.
Igniras
A dragon with a obsidian-like shell and glowing red fissures. It breathes scorching flames capable of melting any metal, and will only obey those who show true potential to become the ultimate ‘Mamong King.’
The “Expedition” System in Board Game Format
In addition to regular training at home, Mamong King features an “Expedition” system for monster development.
This is a board game-style progression where players roll dice to advance. Two distinct expedition destinations are available—summer and winter—with various events and trials awaiting along the way. Deep in remote regions of these expeditions lies battle against ancient Mamons…
Over 170 unique abilities
The game features more than 170 different skills that Mamons can learn.
Skills can be acquired from specific characters or passed down to other Mamons, allowing players to combine and customize their monsters into a truly unique team.
Colorful supporting characters
At the start of the game, players can choose one from two guide characters to assist them on their journey. Together with these companions, strive toward becoming the ultimate ‘Mamong King.’
Thumbnail image for Gallery No. 012 / Monster-raising SLG “Mamong King” produced by Yoshinama, set to launch December 11 on PC/Switch Thumbnail image for Gallery No. 013 / Monster-raising SLG “Mamong King” produced by Yoshinama, set to launch December 11 on PC/Switch
Additional colorful characters also appear throughout the story, including a traveling merchant selling items and an enigmatic mysterious doctor.
Thumbnail image for Gallery No. 014 / Monster-raising SLG “Mamong King” produced by Yoshinama, set to launch December 11 on PC/Switch Thumbnail image for Gallery No. 015 / Monster-raising SLG “Mamong King” produced by Yoshinama, set to launch December 11 on PC/Switch
Game Information
Title: Mamong King
Genre: Monster-raising simulation game
Platforms: Nintendo Switch, PC (Steam)
Number of Players: 1
Release Date: December 11, 2025 (Thursday)
Price: 1,480 yen (tax included) – Available at a special initial 35% discount for 962 yen
Languages Supported: Japanese
Official X Account for Mamong King launched!
Stay updated on the latest news about Mamong King by following our official X (formerly Twitter) account. Be sure to follow now.
Official X (Twitter) Account of Mamong King:
URL: https://x.com/O_mamonking
About Yoshinama
Thumbnail image for Gallery No. 016 / Monster-raising SLG “Mamong King” produced by Yoshinama, set to launch December 11 on PC/Switch
A YouTuber with over 1 million subscribers.
Began posting gameplay videos of action games in 2015.
Known for nearly daily uploads, living his life centered around gaming and sharing authentic moments through video. He also streams almost every day on Twitch, skillfully balancing live streaming and content creation to captivate and inspire a wide audience of young viewers.