Enter the TRUNK(HOTEL), which opened two years ago in Tokyo's bustling Shibuya district. With only 15 rooms, Trunk was arguably the capital's first ''lifestyle hotel'': small and stylish. Now that the Olympics are around the corner, more boutique options have sprung up, but the Trunk remains the leader of its class. Certainly its exterior of geometric grey stone and terraced greenery is among the city's most Instagrammed.

''Our guests can afford luxury hotels but prefer to stay here because it feels new,'' says Haruka Osaka, a Trunk spokesman. The hotel exudes a sense of the cutting edge, starting with that striking facade of two adjacent four-storey buildings which nonetheless blend in with the hilly neighbourhood renowned for its fashion-forward shopping.

On the inside, a spacious lounge lined with upcycled Japanese wood acts as a cafe-cum-community centre. During the day the scene is so genuinely vibrant it looks like an architect's rosy rendering of a co-working space. Twenty-somethings sit on beanbags - and potent macchiatos from local roaster Rostro Japan - for hours at a time, hatching what can only be assumed are plans for the next big start-up. The rooms might have you rethinking what to expect from hotel accommodations. The Dining Suite, for instance, resembles an especially handsome Airbnb in dimensions and facilities. At 82 square metres, with an additional loft space, it's cavernous for a hotel room. Families will appreciate the full kitchen, with everything from colanders to food scales provided, and there are other homey touches, such as a record player and a mid-century modern dining table that seats six.

The Terrace Suite, which sleeps eight, is another standout - an enormous duplex with a private terrace overlooking the Shibuya rooftops. There's a propane grill; a wine cellar; a walk-in wardrobe. Lying on the butterscotch-coloured leather sofa looking out on the terrace's lush greenery, you might start to think of the Trunk as your home, but better.

Yet even the regular rooms, which make up half the hotel's offerings, are thoughtfully appointed. Some feature small balconies with hammocks and beanbags, but all boast a minibar Monocle magazine named the world's best. Even the cola is artisanal at Trunk, and there is also house-brewed beer, coffee syrup and a well-edited selection of Japanese lollies.

An uncommon attention to detail extends to even the most quotidian of the rooms' objects. The hair comb is made by mixing fine paper powder with plastic raw material and the toothbrush was a keeper, with a durable handle from recycled materials. (The toothpaste was made with organic tea leaves, naturally.)

Believe it or not, the toiletries tie in with the hotel's theme, which is ''socialising''. Osaka explains this somewhat oblique concept: ''There is no equivalent in Japanese, but it means being good in society, not just spending money but spending it on objects which are durable and which are good for the world.'' That's why, along with its more expensive, slightly generic all-day restaurant, Trunk Kitchen, the hotel offers a budget dining option. Trunk Kushi, which sits on the street, tends to attract crowds of jovial locals who come for all-you-can-eat skewers and craft beer'. Kushi is an excellent option if you're slightly sweaty from a day navigating the peaks and valleys of the area on one of the hotel's bikes.

In August, the Trunk group opened a new property with a dramatically different concept but operating under the same socially conscious principles. TRUNK(HOUSE), in Kagurazaka, a historic slice of a neighbourhood untouched by modernity, is a 70-year-old geisha house designed for a group of six. Although the building is ancient for Tokyo, it has been lavishly renovated. There's a private indoor garden, a disco floor with wet bar, and a cypress tub with ''adult artwork'' on the surrounding tiles. ''It's for Japanese people who feel nostalgic, but it's also for international visitors who want to learn more about Japanese culture,'' says Osaka. Like Trunk Hotel, it sounds perfect for visitors who want to see Tokyo, but also socialise there.