Hello there. Today I'd like to introduce "Isekai Tsushin (Smartphone Edition)."

Created by the circle "Hige to deko," this is a dark erotic doujin smartphone game set on a remote, isolated island. The genre tags include bondage, decadence, depravity, and trance — if those themes are your thing, just glancing at the product page is probably enough to get your pulse racing.

The story takes place on a solitary island far out at sea, where a warp device has been secretly under development. Before it can be completed, the device activates on its own, tearing open a gateway to another world. Grotesque creatures come pouring through. A high school girl named Fuyuko, who happens to be an anti-demon exorcist, draws her sword to protect the island's inhabitants — and so our tale begins. Despite the sudden, ambush-like opening, the worldbuilding is surprisingly thorough, and you'll find yourself naturally drawn deeper into the story as it unfolds.

The game features four distinctive heroines:

• Fuyuko: The main heroine. A cool beauty and high school exorcist. What lies hidden beneath that composed exterior? You'll have to see for yourself.
• Rio: Granddaughter of the warp device's developer and the protagonist's classmate. A strong-willed sub-heroine.
• Chiaki: A married woman living on the island. She has a background as a former gravure idol, yet her genuine love for her husband is also depicted — a contrast that perfectly highlights the allure of the decadence and depravity themes.
• Shizune: A police officer from the Paranormal Incidents Division. She carries an aura of cold ruthlessness, and that gap adds a compelling layer of tension to the narrative.

In terms of scenarios, the game is packed with decadent, immoral content — brainwashing (hypnosis), training, confinement, lewd examinations, and more. Bondage and candle wax elements are also included, making this a title that delivers for anyone looking for a game that truly pushes boundaries.

The sheer volume of adult content is another highlight: 45 base CGs (excluding standing sprites) and over 200 scenes. The creator, Deko, has stated that they "poured everything into the ero content," and that dedication clearly shows in the density of what's on offer. The response from buyers has apparently exceeded expectations as well — 150 copies sold has been a major source of encouragement for the circle. The abundance of satisfied feedback speaks volumes about the quality of this title.

The combat system features a simple design, making it easy to progress without frustration even if action games aren't your forte. The convenience of being playable on a smartphone also adds to the game's accessibility. It's the kind of title you could secretly enjoy during a commute or right before bed.

After clearing the game, a scene recall feature is available, letting you revisit your favorite moments at your leisure. It's a welcome touch that the game is designed for repeat enjoyment rather than being a one-and-done experience.

In the creator Deko's own words, there's a sincere passion for their craft — "I always carry the desire to make the ero content better than last time." Because this title was born from such an earnest creative spirit, it's well worth picking up. If the world of decadence and depravity calls to you, take your time and lose yourself in this island's story at your own pace.