Calum Henderson: Terrace House is a gentle but compelling watch

The cast of Terrace House.

Terrace House, the Japanese reality franchise that has built a cult following since arriving on Netflix a couple of years ago, is a surprisingly difficult show to describe.

Your first instinct might be to call it "Japanese Big Brother", but that only holds up insofar as its stars all live together in a big house. There are no challenges, no eliminations, no winners or losers. Housemates are free to stay as long as they like and can leave whenever they want.

The romantic subtext is important - the housemates are generally young, attractive and eager to couple up (the crude Kiwi aphorism "don't screw the crew" clearly doesn't have a Japanese translation). But here it unfolds at such a slow pace that it feels relaxing to watch, about as far from Love Island or Married at First Sight as TV could possibly get.

Despite the barrier of subtitles, it is a genuinely funny show. The missing link in explaining its appeal, weirdly enough, might be Seinfeld. If that was the original "show about nothing", then Terrace House is the reality show about nothing. Its magic lies in the observational way it elevates everyday social interactions to high comedy as much as high drama.

The latest series, Terrace House: Opening New Doors, arrived on Netflix last week in typically low-key fashion. After arriving at the house in the picturesque resort town of Karuizawa, the housemates introduce themselves around the dining table. Later, they go to the supermarket to shop for ingredients and cook dinner. The episode's climax comes when 19-year-old Yuudai shocks his roommates by revealing that he sleeps with two stuffed toy pandas from Ikea.

This particular type of nothing, it turns out, is one you can watch for hours.

At first it all feels so polite and formal, but once you become more attuned to the show's rhythms it becomes clear that everyone is just as manipulative and shady as anyone on any other reality show - they're just way more subtle about it. Sometimes it takes the panel to explain how a seemingly innocuous conversation was in fact loaded with tension.

The panel is Terrace House's biggest point of difference, its secret weapon: every 10 or 15 minutes the show cuts back to the studio, set up like a living room, where six comedians, actors and celebrities are watching the action.

Their reaction and analysis, happening in close to real time, is the highlight of every episode.

The trip to the supermarket, for example, introduces us to the "hot pot sergeant" - the oldest housemate, 31-year-old snowboarder Taka, earns this designation for taking control of the shopping trip, despite the fact that Yuudai is a trained chef.

After watching aspiring model Ami badmouth Yuudai's breakfast soup to her friend, bespectacled comedian Ryota Yamasato takes a sudden, vitriolic dislike to her. A hacky joke from goofy Yoshimi Tokui earns a mocking response from Azusa Babazono: "What are you, a comedian from the Edo period?"

The panel's specialty is romantic speculation.

By the end of the first episode they are already wondering if Yuudai might get together with Ami, or if tomboyish ice hockey player Tsubasa, the popular favourite, will find love in the house.

Who wouldn't want to watch along with them and find out?

Lowdown

Terrace House: Opening New Doors (Netflix)