BODY: Rimuru Tempest has conquered dungeons, unified monsters, and founded a nation โ but leading an idle RPG's roster of bishoujo characters in a bunny costume may be a first even for the world's most overpowered slime.
On September 5, C4 Connect released a new promotional video for the ongoing collaboration between its free-to-play idle RPG Houchi Shoujo ~Hyakka Ryouran no Moehime-tachi~ (known internationally as Idle Princess) and the hit anime That Time I Got Reincarnated as a Slime (Tensura). The tie-up brings the anime's core cast into the game as playable heroines, decked out in the crossover's signature bunny-suit designs.
The new PV showcases the collaboration lineup, with Rimuru joined by fan favorites reimagined in the game's characteristic art style. Beyond the headline characters, the event rolls out a steady stream of limited-time content: login campaigns, exclusive missions, and gacha banners offering the crossover units โ the standard toolkit for keeping Houchi Shoujo's long-tail player base engaged during a high-profile brand partnership.
Houchi Shoujo has been a quiet juggernaut in Japan's mobile market for years, built on a formula of auto-battling, historically-inspired heroines, and aggressive collaboration campaigns. Pairing it with Tensura โ one of the biggest isekai franchises of the past decade โ is a natural fit, tapping two of otaku culture's most reliable engines: idle progression and reincarnation fantasy.
Players looking to recruit Rimuru and company should jump in while the limited events are live.
The insider take
Idle RPGs like Houchi Shoujo live and die by their collaboration calendar. In Japan, where the mobile market is saturated and player acquisition is brutally expensive, a Tensura tie-up isn't just fan service โ it's a growth strategy, borrowing an established anime's audience to reactivate dormant accounts and lure new ones. The bunny-suit motif is a deliberate signal, too: it tells veteran players this is a "special" premium event worth spending on, a visual shorthand the genre has trained its whales to recognize instantly.
Originally reported by AUTOMATON (Japanese).